Unit 5 - Computer Network

Packet-switching

Files broken into data packets with headers for routing

Network Interface Card (NIC)

Built-in device for network connection, wireless or wired

Media Access Control (MAC) address

Unique address assigned to NIC by manufacturer

Router

Sends data packets to networks closer to destination

Switch

Connects nodes in a network, routes data to correct computer

Hubs

Send data to all connected computers in a network

Wireless networks

Connect using Wi-Fi and broadcast via radio waves

Wireless Access Point (AP)

Device enabling wireless devices to connect to a wired network

LAN

Local Area Network on a single site with shared resources

Topology

The way parts of a system are connected

Star topology

Nodes connected to a central switch for fast data transfer(uses copper cables,

Advantages include individual wire connections and minimal impact if one cable fails.

Bus topology

Devices connected to a central coaxial cable in a linear fashion

Advantages include cost-effectiveness and ease of adding more devices.

Copper cable features

Adequate speed, low cost, affected by electrical interference

Fibre Optic cable features

Very fast, high cost, immune to electromagnetic interference

PAN

Personal Area Network connecting devices near a person

Bluetooth

Wireless method for short-distance device connections

Advantages of wireless Networks

No need for cables, easy to connect new devices.

Devices can be portable within the access point range.

Disadvantages of Wireless Network

Can be less reliable and slower with many devices connected.

Connection speed decreases with distance from the access point.

LAN (Local Area Network)

Operates on a single site with its own cabling system.

Allows resource sharing, easy file access, and centralized data backup.

Computer Network

Two or more computers connected to share information and resources

WAN

Network covering a large geographical area using third-party resources

Protocol

Set of rules governing communication in a network

HTTP

Protocol for accessing web pages on the Internet

HTML

Language for creating web pages

HTTPS

Secure version of HTTP encrypting data

FTP

Protocol for transferring files to/from an FTP server

SMTP

Protocol for sending emails to a mail server

POP

Protocol for downloading emails to a local device

IMAP

Protocol for leaving emails on a server accessible by multiple devices

TCP

Protocol breaking messages into packets, reassembling, error detection, and resending

IP

Protocol routing packets between IP addresses

TCP/IP Protocol Stack

Defines layers for Internet communication: Application, Transport, Internet, Link

Application Layer

Layer where applications create data for transmission

Transport Layer

Establishes connections between hosts, divides data into packets

Internet Layer

Responsible for routing packets, operated by routers

Link Layer

Handles MAC, Ethernet, and Wi-Fi for physical connections