Comptia A+ Flashcards ionicons-v5-c

PS/2 port

6-pin mini DIN port that connects keyboards or mice on legacy computers; not interchangeable between them

CGA

Color Graphics Adapter - Supports 4 colors at 320x200 or 2 colors at 640x200

EGA

Enhanced Graphics Adapter - 16 colors at 640x350

VGA port

Video Graphics Array; 15-pin, three-row D-subminiature connector. Other names: DB-15, DE-15, HD-15

VGA

Video Graphics Array - 16 colors at 640x480 or 256 colors at lower resolutions

XGA

Extended Graphics Array - 65,536 colors at 800x600 or 256 colors at 1024x768

Wide XGA

1366x768 resolution

XGA+

1152x864 resolution

Wide XGA+

1440x900 resolution

SVGA

Super Video Graphics Array, 16M colors, 1280x1024

Super XGA

Super Extended Graphics Array, 1400x1050

WSXGA+

Widescreen SGA+ 1680x1050

Ultra XGA

1600x1200

WUXGA

Widescreen Ultra Extended Graphics Array - 1920x1200

DVI port

Digital Visual Interface; accepts both analog and digital signals but only through specific connectors. DVI-D, DVI-A, and DVI-A/D or DVI-I. DVI-I and DVI-D also support Dual-Link connections by having extra pins.

DisplayPort

Compact 20-pin connector; supports up to 2560 x 1600 and 120 Hz refresh rates. Can drive up to four displays by a single port and is capable of signal encryption and transmission of audio. Also comes in Mini Displayport.

HDMI

High Definition Multimedia Interface; also comes in mini and micro variations

S/PDIF

Sony/Phillips Digital Interface; digital audio output that comes in both electrical and optical variations. Electrical usually uses RCA on coax, optical uses fiber.

RG-6 cable

Coaxial connection 75 Ohms

RG-59 cable

Coaxial connection 75Ohms

F connector

Coaxial connector, pin center, outer threaded ring

Component video

Uses 3 RCA connectors that split the signal into its components, 1 for brightness and 2 for color (Yellow, red, white)

S-Video

Sends video signal from a computer to a TV, shaped similarly to PS/2

MIDI/Joystick port

On legacy systems, a female DB-15 port with the pins arranged in 2 rows instead of 3

ST connector

Fiber connector (stick it in and twist it)

SC connector

Fiber connector (stick and click)

LC connector

Fiber Connector

BNC connector

Bayonet-style coax connector used for 10Base2 or Thinnet networking

FDDI, MT-RJ, and FC

Fiber internet connectors, less popular

USB Max devices

Can support up to 127 devices on a single port

USB 1.0/1.1 Low speed data rate

Conn type with 1.5 Mbps max speed

USB 1.0/1.1 Full Speed data rate

Conn type with 12 Mbit/s speed

USB 1 Max Length

Conn type with 3 meters

USB 2.0 Hi-speed data rate

Conn type with 480 Mbps max speed

USB 2.0 Hi-speed max length

Conn type with max length 5 meters

SuperSpeed USB 3.0 data rate

Conn type with 5 Gbps max speed

SuperSpeed USB 3.0 max length

Conn type with max length 3 meters

SuperSpeed+ USB 3.1 max speed

Conn type with 10 Gbps max speed

SuperSpeed+ USB 3.1 max length

Conn type with max length 3 meters

IEEE 1394a firewire max speed

max speed 400 Mbps

IEEE 1394a firewire max length

4.5 meters cable length

Firewire no of pins?

6 pin connector

IEEE 1394a firewire max devices

Conn type with 63 max devices

IEEE standard for firewire?

1394a standard better known as?

IEEE 1394a

Firewire 400, 6 pins, 400Mbps

IEEE 1394b

FireWire 800 - 9-pins, max speed 800 Mbps;

Firewire S1600 speed

Connection runs at 1.57Gbps

Firewire S3200 speed

Connection runs at 3.14 Gbps

Firewire max devices

Technology that allows 63 devices in a daisy chain

Thunderbolt connector

Combines PCIe and DisplayPort into a single connection, used for peripherals. Max length 3 m on copper, 60 m on fiber

Thunderbolt distance

provides 100M with optical, 3M with copper

Thunderbolt 1

Max speed 10 Gbps; MDP connector

Thunderbolt 2

Max speed 20 Gbps; MDP connector

Thunderbolt 3

Max speed 40 Gbps; USB Type-C connector

EMI

Electromagnetic Interference; occurs when two signals in close proximity interfere with each other

UPS

Uninterruptible Power Supply

SPS

Standby Power System; monitors power line, incurs split-second delay as power switches over

Online UPS

Acts as system's power source while charging internal batteries; switches instantly to battery during an outage; most also act as power conditioners

Line-interactive UPS

SPS with added circuitry for moderate AC surges and sags; may increase current consumption loads on fuses or circuit breakers

BIOS

Basic Input/Output System

TPM

Trusted Platform Module; hardware platform for accelerating cryptographic processing; commonly used for hard drive encryption

Secure Boot

Requires drivers and OS software to be properly signed by a trusted party; only available on Intel CPUs with UEFI BIOS and OS designed for it

UEFI

Unified Extensible Firmware Interface

NMI

Non-Maskable Interrupt

NIC

Network Interface Card

FRU

Field Replaceable Unit (spare part)

MSDS

Material Safety Data Sheet

Active PFC

Active Power Factor Correction; eliminates harmonics

JBOD

Just a Bunch of Disks

FAT 16 partition and file size limits

2.1 GB max partition size; no local file-level security & limits files to 4 GB

FAT 32 partition and file size limits

2 TB max partition size; no local file-level security & limits files to 4 GB

exFAT partition and file size limits

2 TB max partition size currently, theoretically supports up to 128 PB; no local file-level security (FAT 64)

NTFS

New Technology File System; has permissions, encryption, and disk quotas

MFT

Master File Table; used by NTFS; critical parts backed up in middle of disk

HFS+

Hierarchical File System Plus; used by Mac OSX; can read and write to FAT32 and exFAT; read-only support for NTFS

ext4

Fourth Extended File System; Linux; supports 1 EB volumes, 16 TB files; backwards-compatible with ext3 and ext2; can read and write to NTFS, FAT32, exFAT, HFS+, ext2, ext3, ext4

SMART

Self Monitoring, Analysis, and Reporting Technology; sed by HDDs and SSDs to detect failures

DVD Single Layer

4.7 GB capacity

DVD Dual Layer

8.5 GB capacity

RAID

Redundant Array of Independent Disks

RAID 0

Striping

RAID 1

Mirroring

RAID 5

Striping with parity; only protects against single drive failure

RAID 1+0

Stripe of Mirrors; best redundancy

GUID

Globally Unique Identifier; a unique ID number hard coded into bios/cmos

GPT

GUID Partition Table; newer basic disk partitioning scheme that requires UEFI

MBR

Master Boot Record; older basic disk partitioning scheme

MBR's job

To check the partition table for a partition with a valid OS; only 1 MBR and 1 partition tablw exist per disk

Number of partitions MBR supports

Format supporting 4 partitions

Max disk capacity of MBR

Format supporting 2.2 TB disk capacity

EFS

Encrypting File System; feature of NTFS

> format f: /fs:ntfs

Formats drive f: with NTFS file system

EPROM

Erasable Programmable Read-Only Memory

EEPROM

Electrically Erasable Programmable Read-Only Memory

CMOS

Complementary Metal-Oxide Semiconductor

NLX

Mobo form factor with a riser to add on all expansion slots

SFF

Small Form Factor; motherboard classification

LPX

Low-profile eXtension; risers

PCI

...

PCIe

...

PCI-X

...

ITX

...

mini-ITX

...

mini-ATX

...

PCI-X

...

AGP

...

What is primary storage

RAM is what kind of storage?

What is secondary storage

HDDs and SSDs are what kind of storage?

PGA

Pin Grid Array

Intel procs - PGA or LGA?

Which Procs are LGA, not PGA?

LGA

Land Grid Array

AMD Procs - PGA or LGA?

Which Procs are PGA, not LGA?

ZIF

Zero Insertion Force - Allows proc to be put in without force. Lever locks in place and makes pin contact.

P4

4 pin Motherboard connector supplying additional +12VDC to the CPU

Northbridge

Part of mobo that controls AGP, PCIe and Memory

Southbridge

Part of mobo that controls PCI, IDE, USB, ISA

RTC

Real-time Clock

SDRAM

Synchronous Dynamic RAM 168 pin DIMM, 2 notches, synced to system clock speed

DDR RAM

Double Data Rate RAM, 184 pin DIMM, Single Notch,

DDR pins and volts

Memory with 184 pins and 2.5V

DDR2 pins and volts

Memory with 240 pins and 1.8V

DDR3 pins and speed

Memory with 240 pins runs at 4x mobo bus speed

PC-100

100MHz SDRAM, 168Pin DIMM, 2 notches, tied to system clock

PC-133

133MHz SDRAM, 168Pin DIMM, 2 notches, tied to system clock

PC-1600

DDR-200, 100MHZ bus, 2.5V 184 pin DIMM

PC-2100

DDR-266, 133MHZ bus, 2.5V 184 pin DIMM

PC-2400

DDR-300, 150MHZ bus, 2.5V 184 pin DIMM

PC-2700

DDR-333, 167MHz bus, 2.5V 184 pin DIMM

PC-3200

DDR-400, 200MHz bus, 2.5V 184 pin DIMM

PC2-3200

DDR2-400, 200MHz bus, 1.8V 240 pin DIMM

PC2-4200

DDR2-533, 266MHZ bus, 1.8V 240 pin DIMM

PC2-5300

DDR2-666, 333MHZ bus, 1.8V 240 pin DIMM

PC2-6400

DDR2-800, 400MHZ bus, 1.8V 240 pin DIMM

PC2-8500

DDR2-1066, 533MHz bus, 1.8V 240 pin DIMM

PC3-6400

DDR3-800, 400MHZ bus, 1.5V 240 pin DIMM

PC3-8500

DDR3-1066, 533MHz bus, 1.5V 240 pin DIMM

PC3-10600

DDR3-1333, 667MHz bus, 1.5V 240 pin DIMM

PC3-12800

DDR3-1600, 800MHz bus, 1.5V 240 pin DIMM

DIMM

Dual In-line Memory Module

DIMM data path bit size

what memory type has 64-bit data path?

SDRAM pins

memory with 168 pins

DDR pins

memory with 184 pins

DDR2 and DDR3 pins

memory with 240 pins

SODIMM

200 pin Small Outline Dual Inline Memory Module (for laptops)

How many pins does SDR SDRAM use?

What memory has 168 pins?

How many pins does DDR SDRAM use?

What memory has 184 pins?

Raid 0

Spanning - Multiple drives acting as one single drive. Provides ZERO redundancy.

Raid 1

Mirroring - Multiple drives acting as Clones of eachother. Provides redundancy, but limited to 2 physical drives.

Raid 5

Block Level Striping - Multiple drives. Parity is distributed across all drives. Will fail if 2 drives go down at same time.

Raid 10 or 1+0

Stripe of Mirrors min of 4 drives

Striping

Dividing data into blocks and spread it across disks. Higher performance, but time to rebuild.

Mirroring

Cloning data between drives. Provides redundancy.

SCSI

Small Computer Systems Interface for attaching printers, scanners, tape drives, etc.

CD Capacity

74 min or 682MB

BluRay disk capacity

25GB capacity

BDXL

128GB capacity 4 layer bluray

Bluetooth Frequency

UHF radio waves in ISM band from 2.4 to 2.48GHz

Radio Frequency (RF)

3kHz to 300GHz

AM2

940 Pins DDR2 support

AM3

938 pins DDR3 support

Execute Bit EDB

Intel hardware based secuity feature. Allows proc to identify memory areas where code can/cannot execute.

Hyper-threading Technology HTT

Intel technology (ONLY ON INTEL PROCS) makes 1 proc look like 2 to the OS

RG-6/U

Coaxial cable

RJ--11

Telephone connector plug type

RJ-45

Ethernet connector plug type

T568A

network wiring standard Grn/wht, Grn, Org/wht, Blu, Blu/Wht, Org, Brn/wht, Brn

T568B

US Gov network wiring standard

SMF (Single mode fiber)

Fiber for transmitting LASERS. Single ray of light. Costs more, smaller diameter, faster and delivers better distance.

Multi-mode fiber

Fiber for transmitting Multiple rays of regular light from LEDS. Popular fiber type with larger diameter, slower, shorter distance, less expensive.

Class A IP Range

IP Address starts 1 to 126

Class B IP Range

IP address starts 128 to 191

Class C IP Range

IP address starts 192 to 223

NBTStat -n

NBTstat switch which lists local NetBIOS names.

NBTStat -a

NBTStat switch which lists the remote machine's name table given its name

NBTStat -A

NBTStat switch which lists the remote machine's name table given its IP address

NBTStat -c

NBTStat switch which lists cache of remote machine names and their IP addresses

NBTStat -r

NBTStat switch which lists names resolved by broadcast and via WINS

NBTStat -R

NBTStat switch which purges and reloads the remote cache name table

NBTStat -s

NBTStat switch that lists sessions table converting destination IP addresses to computer NETBIOS names.

NBTStat -S

NBTStat switch that lists sessions table with the destination IP addresses

ASIC

Application Specific Integrated Circuit used in Switches

WIndows "ipconfig" in linux:

Linux "ifconfig" in windows:

AMD Trinity processor uses what slot?

FM2 slot used for what proc?

DHCP process

Uses DORA process: Discover, Offer, Request, Acknowledge

MIMO MultiIn MultiOut used in?

802.11n uses what tech for multiple connections?

Display with highest contrast ratio

Plasma display unique feature

Command replaced scandisk

Chkdsk replaced what command?

SPI

Stateful Packet Inspection - a function of firewalls

Best printer humidity range

between 25% and 50%

Sata 1 Speed

1.5Gbps (or 150MBps)

Sata 2 Speed

3 GBps (or 300 MBps)

Sata 3 Speed

6 GBps (or 600 MBps)

Sata 3.2 Speed

16Gbps (or 1969 MBps)

PCI bits and Hz

32bits and 33MHz

PCI-X bits and Hz

64bits and 133MHz

PCIe speed calc

Lane speed * # of lanes

Sata1 speed

1.5Gbit/sec

Sata2 specs

3.0 Gbit/sec and Native Command Queueing

eSata specs

Host speed Gbit/sec

eSata cable length

cable length limit of 2 meters

Sata3 specs

6.0 Gbit/sec

ISO9660

ISO descriptor for CD data storage format

DVD9

Single Sided, Dual Layer DVD

Single Layer Blu-Ray Capacity

25GB storage on blu ray

Dual-Layer Blu-Ray Capacity

50GB storage on blu-ray

HDCP High Bandwidth Digital Content Protection

Blu-Ray protection technology

Serial Port Connector Type

Port with DB9 9-pin connector

Yost or Rollover cable

Blue cable with eth on one end and serial on the other for comm to routers/firewalls

Mouse Keys

Use arrow keys instead of mouse

Sticky Keys

Holds keys down for you for multi-key combos (like CTRL-ALT-DEL)

Activate Sticky Keys

Left shift 5x

Filter Keys

Ignores double taps on keys

Toggle Keys

Tone when you press CAPS LOCK, NUM LOCK or SCROLL LOCK

CDDA

Orig format of audio CDs

PCI Speed

...

AGP Speed

...

EPP Mode

Enhanced Parallel Port mode - Allows bi-directional comms up to 2MBps and daisy-chaining

CompTIA troubleshooting method

1-ID the Problem2-Establish theory of cause3-Test Theory / Determine Cause4-Plan Resolution Action / Implement Solution5-Verify Functionality / Apply preventative if necessary6-Document steps/findings

CompTIA troubleshoot method Step 1

Identify the problem

CompTIA troubleshoot method Step 2

Establish a theory of cause

CompTIA troubleshoot method Step 3

Test Theory / Determine Cause of Problem

CompTIA troubleshoot method Step 4

Plan Action to Resolve Problem / Implement Solution

CompTIA troubleshoot method Step 5

Verify Functionality / Apply preventative maintenance if necessary

CompTIA troubleshoot method Step 6

Document outcome / findings

Pentium 4 Sockets

Processor using sockets: 423 or 478

Intel Core i5 Sockets

Processor using sockets 1150, 1155, 1156

Intel Core i7 Sockets

Processor using sockets 1366 or 1156

MAC Address

12 Hex character address defining network hardware. First 6 characters are Manufacturer code.

CAT3 cable

10Mbps network cable standard

CAT4 cable

16 Mbps cable standard

CAT5 cable

100 MB/sec cable standard

CAT5e cable

1 GB/sec cable standard

CAT6 cable

250 MHz cable standard, 10 GB/sec over shorter dist

CAT6A cable

250 MHz, 10GB over 100M cable standard

CAT7

600 MHz 100 GB/sec cable standard

Number of Bites in a Frame

1500 bites comprise what network package?

APIPA address

169.254.x.x where x is random numbersand subnet 255.255.0.0

What is APIPA?

Automatic Private Internet Protocol Addressing - when auto IP but cannot find DHCP server

Localhost

loopback or 127.0.0.1

broadcast ip

255.255.255.255

Private IP range

starts with 10.x or 172.16.x to 172.31.x or 192.168.x

TCP

Transmission Control Protocol - How to talk using IP - Connection oriented, connection is negotiated

UDP

User Datagram Protocol - Connectionless -

ICMP

Internet Control Message Protocol - Used by PING - Connectionless - Only ONE packet of data

Command to query DNS server

nslookup [ip address]

LLMNR

Link Local Multicast Name Resolution (better than Netbios, on

Netbios status of <0>

Netbios status of workstation

Netbios status of <20>

Netbios status of server

Port Triggering

Router temporarily opens incoming ports if internal IP has instigated comms

QOS

Quality of Service - manages bandwidth by service/port number

Sempron

Amd 64bit proc (formerly 32 bit), Low end ver of the Athlon64. Replaced the Duron.

Turion

AMD 64 bit proc for laptops

Athlon 64 X2

AMD dual core proc for desktops, competes with Intels Pentium 4.

Athlon 64

AMD single core proc for desktops, competes with Intel Pentium 4

Phenom

AMD triple/quad core proc, AM2+ socket, L3cache=2MB, 1.8-3.0 GHz

Phenom II

AMD triple/quad core proc, AM2+ socket, L3 cache=6M, 3core-2.6-2.8GHZ, 4core=2.5-3.0GHz

Procs for Socket A

Athlon, Athlon XP and Duron

Superscalar

Processor feature when it has more than one instruction pipeline (intro on Pentium proc)

Another term for Socket R

Another term for LGA2011

Socket type for i7 on servers/high end systems

Proc for Socket R (aka LGA2011)

Pentium 4 sockets

Proc for Socket 423 or 478

How to turn a Pentium into a Celeron?

What happens when you cut L2 cache out of a Pentium?

ISDN speed

Connection with 128 KBps data rate

POTS speed

Connection with 56 KBps data rate

LTE

Long-Term Evolution - The primary form of wireless 4G cellular internet connection

WIMAX

Worldwide Interoperability for Microwave Access - A form of wireless 4G connection

MAN

Metropolitan Area Network - Citywide wireless 802.11

What tier is an ISP?

Tier 3 internet access

APM

Advanced Power Management - Old power config standard

ACPI

Advanced Configuration and Power Interface - Current power config standard

COM1 Default IRQ

Port with Default IRQ=4

COM1 Default I/O

Port with Default I/O=3F8-3FF

LPT Default IRQ

Port with Default IRQ=7

COM2 Default I/O

Port with Default I/O=2F8-2FF

COM2 Default IRQ

Port with Default IRQ=3

LPT Default I/O

Port with Default I/O=378-37F

Disk Size Formula

# of Cylinders Heads # of sectors/track * 512bytes/sector

IDE max size

528MB

EIDE transfer rate

16MBps and higher

SCSI-1 Transfer Rate and Bits

Connection with 5 MB/sec transfer rate and 8 bits

Fast SCSI-2 Transfer Rate and Bits

Connection with 10 MB/sec transfer rate and 8 bits

Wide SCSI-2 Transfer Rate and Bits

Connection with 10 MB/sec transfer rate and 16bits

Fast Wide SCSI-2 Transfer Rate and Bits

Connection with 20 MB/sec transfer rate and 16bits

Ultra SCSI Transfer Rate and Bits

Connection with 20 MB/sec transfer rate and 8 bits

Ultra Wide SCSI Transfer Rate and Bits

Connection with 40 MB/sec and 16 bits

LVD Ultra 2 SCSI Transfer Rate and Bits

Connection with 80 MB/sec and 16 bits

IDE max cable length

18 inch cable length

SATA max cable length

39 inch cable length

Sata V1 max and transfer rate

1.5 GB/s max and 150MB/s transfer rate

Sata V2 max and transfer rate

3.0GB/s max and 300 MB/sec transfer rate

Sata V3 max and transfer rate

6.0GB/s max and 600 MB/sec transfer rate

CD Data Rate

150 KB/sec

CD 4x Data Rate

600 KB/sec

CD 8x Data Rate

1200 KB/sec

DVD Data Rate

1.35 MB/sec

DVD 2x Data Rate

2.7 MB/sec

DVD 8x Data Rate

10.8 MB/sec

BluRay Data Rate

4.5 MB/sec

Sector size

512 Bytes

Laser print process

1-charge (condition) the drum via corona wire2-Write - laser image on drum3-Develop -toner jumps from develop roller to drum where laser hit4-transfer toner from drum to paper5-fuse image6-cleaning

802.11a

wireless 54Mb/sec

802.11b

wireless 11 Mb/sec

802.11g

wireless 54 Mb/sec

802.11n

wireless 600 Mb/sec

802.11ac

wireless 1.3 Gb/sec

Windows print spool directory

%systemroot%\system32\spool\printers

Windows Vista - Min Proc

800MHz or better for this OS

Windows Vista - Min Memory

512MB or better for this OS

Windows Vista - Min HDD

20GB with 15GB free for this OS

Windows Vista - Min Display

DX9.0 min display for this OS

Windows 7 - Min Proc

1GHZ 32/64 proc for this OS

Windows 7 - Min Memory

1GB (32 bit) or 2GB (64 bit) memory for this OS

Windows 7 - Min HDD

16GB (32 bit) or 20GB (64 bit) hdd space for this OS

Windows 7 - Min Display

DX9.0 with WDDM1.0 display for this OS

Windows 8 - Min Proc

1GHZ 32/64 proc for this OS

Windows 8 - Min Memory

1GB (32 bit) or 2GB (64 bit) memory for this OS

Windows 8 - Min HDD

16GB (32 bit) or 20GB (64 bit) hdd space for this OS

Windows 8 - Min Display

DX9.0 with WDDM1.0 display for this OS

Windows 8 - Install Special Requirements

Requires access to windows store and resolution of 1024x768

ls /bin/p* | grep wd

Linux list all files starting with "p" and containing string "wd" in the filename or path

chmod g+wx myfile.txt

linux add group write and execute permissions to myfile.txt

chmod -l

linux command to see local dir file info including permissions

ifconfig

Linux view status of wired network interfaces

iwconfig

linux view status of wireless network interfaces

ifconfig eth0 down

linux disable of first wireless network interface

ps -ax

linux list all running processes for both terminal and system

apt-get install nano

linux install application nano

apt-get remove nano

linux uninstall application nano

the 4 apt-get switches

1-update2-upgrade3-install4-remove

Mac OSX min proc

OS requires PowerPC G3 processor

boot.ini in older OS is now what?

BCD (Boot Configuration Database) on new OS was formerly known as?

Boot order for windows

bootmgr > winload.exe > ntoskrnl.exe

Dir /ad

Dos command for listing directories only

Dir /b

Dos command for bare listing of filenames only

Dir /og-d

Dos command for directory listing sorted in reverse date order with files groups separately from directories

dir /s

Dos command for directory listing including all subdirectories

Dir /x

Dos command for newer windows systems that lists both long and short filenames in current directory

Set Dircmd=/on /w

Dos command to set env variable so dir listings always show in wide format

Name the 4 areas of system bottlenecks

Processor, Memory, Disk, Network are what?

HOSTS file

File used to resolve FQDNs into IP addresses

LMHOSTS file

File used to resolve NETBIOS names into IP addresses

2 ways to resolve FQDNs to IP

DNS and HOSTS file

ARP function

Way to resolve IP to MAC address

DNS

Protocol to convert FQDns to IPs

DHCP

Protocol to hand out IP addresses to network devices

LDAP

Internet protocol for accessing a directory service

SNMP

Protocol allowing remote management of a device

SMB/CIFS

Protocol for allowing Microsoft systems to share resources

SSH

Secure file transfer protocol replacing telnet

AFP

Protocol allowing Apple systems to share resources

NNTP

Protocol for transferring articles between news servers and news clients

SFTP

Protocol for file transfer, replaces FTP, more secure

SSL

Used to encrypt web traffic. Identified by the lock on browser screen.