CompTIA A+ 220-1201 First Seven Videos

Modular battery

Removable by the user via a button; easy to swap.

Built-in battery

Requires technician disassembly of the laptop to replace.

Lithium Ion (Li-Ion) memory effect

None; Li-Ion/LiPo can be charged at any time without capacity loss.

Laptop Keyboard Troubleshooting

Plug in an external USB keyboard to isolate hardware vs. OS issues.

SO-DIMM

Small Outline Dual In-Line Memory Module; standard laptop RAM form factor.

Soldered RAM

RAM permanently attached to the motherboard; not upgradeable.

2.5-inch Form Factor

Standard physical size for laptop HDDs and older SSDs.

M.2 SSD

Small card format; provides data and power through one motherboard slot.

Drive Imaging / Cloning

Creates an exact duplicate of an old drive onto a new one.

802.11

The technical standard for Wi-Fi local area networking.

PAN (Personal Area Network)

Short-range wireless network for peripherals, typically via Bluetooth.

Laptop Antenna Placement

Wires are routed around the display frame for maximum height/signal.

Biometrics

Using physical characteristics (face, fingerprint) to authenticate instead of passwords.

NFC (Near Field Communication) Range

Extremely short-range; typically 4 cm or less.

USB-C

Modern 24-pin reversible connector; supports data, video, and power.

Lightning Connector

Apple-proprietary 8-pin reversible connector used on older iOS devices.

Hotspot

Phone acts as a wireless router for multiple devices simultaneously.

Tethering

Sharing a phone's internet connection with exactly one device.

TRRS Connector

Tip-Ring-Ring-Sleeve; 3.5mm jack carrying left/right audio, mic, and ground.

Docking Station

Laptop-specific desk unit supporting expansion cards and full peripheral access.

Port Replicator

Universal USB-connected hub; portable and does not support expansion cards.

Digitizer

An external drawing pad that converts stylus input into digital signals.

3G Notable Additions

Introduced GPS, mobile TV, and video conferencing (1998).

4G/LTE Max Speed

150 Mbps.

5G Max Speed

Up to 10 Gbps at high frequencies.

SIM (Subscriber Identity Module)

Card identifying a phone on a carrier's network; holds phone number.

eSIM

Embedded SIM; built into hardware and updated via software/QR code.

Bluetooth Pairing

One-time setup using a PIN and discoverable mode to link devices.

GPS Satellite Requirement

Requires signals from at least 4 satellites for an accurate fix.

MDM (Mobile Device Manager)

Software for centralized management and policy enforcement of mobile devices.

BYOD

Bring Your Own Device; employee-owned hardware used for work.

COPE

Corporate Owned, Personally Enabled; company-owned but allows personal use.

CYOD

Choose Your Own Device; company-owned, employee picks from approved list.

IMEI

International Mobile Equipment Identity; unique hardware ID burned into the device.

MDM Partitioning

Separating personal data from corporate data on a single device.

OTA (Over-the-Air)

Wireless data synchronization or updates without physical connections.

Encapsulation

Wrapping data in protocol layers (headers/trailers) before transmission.

TCP (Transmission Control Protocol)

Connection-oriented, reliable transport; uses acknowledgments (ACKs).

UDP (User Datagram Protocol)

Connectionless, unreliable transport; prioritized for speed over accuracy.

Well-known Ports

Range 0-1,023; reserved for standard server services.

Ephemeral Ports

Range 1,024-65,535; temporary ports randomly assigned to clients.

FTP Ports

Port 20 (Active Data) and Port 21 (Control).

SSH (Secure Shell)

TCP Port 22; encrypted remote command-line access.

Telnet

TCP Port 23; unencrypted remote command-line access.

SMTP

TCP Port 25; used for sending outgoing email.

DNS

UDP Port 53; translates domain names (FQDNs) into IP addresses.

DHCP Ports

UDP Ports 67 and 68; automatically assigns IP configurations.

HTTP vs. HTTPS Ports

HTTP is Port 80 (unencrypted); HTTPS is Port 443 (encrypted).

POP3

TCP Port 110; downloads email to one device, usually deleting from server.

IMAP4

TCP Port 143; syncs email across multiple devices, keeping mail on server.

SMB/CIFS

TCP Port 445; modern Windows file and printer sharing.

LDAP

TCP Port 389; used to query and manage directory databases.

RDP (Remote Desktop Protocol)

TCP Port 3389; remote view/control of a Windows desktop.