Comp. sci Unit 5, 6

Network

an arrangement of computers and other devices connected to share resources and data

Server

powerful computer that provides the network with a service; storing/ sending/ receiving files and emails

Local Area Network (LAN)

A network that covers a relatively small geographical area, often a single site.

Wireless Local Area Network (WLAN)

a local area network in which connected devices use high frequency waves to communicate

Wide Area Network (WAN)

network that covers a large geographical area

client/server network

network that has at least one server to provide services to the client computers

peer-to-peer network

network that doesn't have any centralized servers.

Bus Topology

network consisting of single cables to which each networked device is connected

Ring Topology

network in which the cable connects one network device to another in a closed loop, or ring.

Star Topology

each network device is connected to a central point.

Mesh Topology - Fully connected

every network is connected to every other network

Mesh topology Partially connected

some network devices may be connected to multiple other networks

Wired connection

methods involve a physical connection between the computer and the network.

Wireless connection

Does not require a physical connection between devices. It transmits and receives radio signals.

Network Data Speed

The speed that data can be transmitted through a communications medium.

Latency

the delay encountered by data traveling through a network

Bandwidth

volume of data being sent

Network Protocols

set of rules that control how communications between devices are formatted and how these connections will be sent/received.

Ethernet (Internet)

protocol that allows computers to talk to each other over wired networks that use devices like routers, switches, or hubs to direct traffic.

WIFI (internet)

commonly used for local area networking of devices and internet access

Transmission Control Protocol (TCP) (Internet)

provides a reliable connection between computers

Hypertext Transfer Protocol (HTTP) (Internet)

allows web browsers and servers to communicate through the exchange of data

HTTP Secure (HTTPS) (Internet)

establishes an encrypted connection between a web browser and server

Simple Mail Transfer Protocol (SMTP) (email)

used when sending emails through the internet

Post Office Protocol (POP)

used for retrieving emails from an email server

Internet Message Access Protocol (IMAP)

allows emails to be accessed using multiple email clients

File Transfer Protocol (FTP)

transferring files from computer to computer

Network layers

makes software and hardware models easier to understand by breaking it down into functional parts

Cellular/mobile network

wireless network distributed through cells

2G

enabled text messages

3G

increased data transmission speeds

4G

Much higher speeds

5G

smarter, faster, and more efficient.

Network Security

range of activities that protect data from threats

Cyber Attack

Any kind of malicious attack on a network

Social Engineering

attacks that rely on exploiting human behavior

Technical weakness

USBS, unpatched software, eavesdropping

Audit trail

a record of activities that have taken place on a computer system.

The internet

connection that links all networks together

Domain name

a unique name that identifies a website on the internet

Domain Name System (DNS)

Internet service that translates domain names into IP addresses.

World Wide Web (WWW)

provides access to web pages which are linked together

TCP/IP network layer: Application

layer which interacts with the user to provide access to services and data that is being sent/received.

TCP/IP network layer: Transport

Layer that manages end-to-end communication over a network.

TCP/IP network layer: Internet

Layer that deals with sending data across multiple networks, from the source network to the destination network.

TCP/IP network layer: Link

Layer that controls the transmission and reception of packets of data to/from a local network.