Networks

standalone machine

a single computer, not connected to anything else

network

connecting one computer device to another, either via cable or wireless

LAN

• local area network

• a network that covers a small geographical area

WAN

• wide area network

• a network that covers a large geographical area

modem

• transforms info into analogue signals, transmitted through wires

router

routes data between devices on a network and the internet

NIC

• network interface controller

• allows communication between computers on a LAN

WAP

• wireless access point

• a device that creates a wireless local area network (WLAN)

hub

• allows you to connect multiple devices to one network

• operates on the physical layer, is considered a passive device

switch

• allows you to connect multiple devices to one network

• operates on the data link layer, is an active device

circuit switching

creates a temporary link of fixed bandwidth between the source and destination that only lasts until the transmission is complete

packet switching

breaks streams of data into smaller blocks, sends them independently

TCP

• transmission control protocol

• provides error free transmission between two routers

IP

• internet protocol

• routes packets across a WAN

UDP

• user datagram protocol

• sends short messages using datagrams

HTTP

• hypertext transfer protocol

• client and server send and receive requests and deliver HTML pages

FTP

• file transmission protocol

• used for sending files between computers on a WAN

POP

• post office protocol

• retrieves emails from a mail server and transfers them to your device, removing them from the server in the process

IMAP

• internet message access protocol

• keeps emails on the mail server, maintains synchronicity between devices

SMTP

• simple mail transfer protocol

• transfers emails between servers and email clients

application layer (four-layer TCP/IP protocol model)

• network applications operate at this layer

• FTP, HTTP, SMTP

transport layer (four-layer TCP/IP protocol model)

• sets up communication between two hosts

• TCP, UDP

internet/network layer (four-layer TCP/IP protocol model)

• addresses and packages data for transmission, routes packets across the network

• IP

link layer (four-layer TCP/IP protocol model)

network hardware and connection port standards

domain name system

1. user requests a URL via a browser

2. browser sends the domain name to a domain name system (DNS)

3. the DNS maps the domain name to an IP address and returns it to the browser

4. a GET request for the web page or resource is returned to the client’s web browser