Networks

• LAN Local Area Network: A network of computers within the same building such as a school home or business.
• WAN Wide Area Network: Can connect organisations based in different geographical places. Uses 3rd party infrastructure (BT cables etc). The internet is an example of this.
• Network topologies: bus Each computer and network device are connected to a single cable or backbone
• Network topologies: star Each device on the network has its own cable that connects to a switch or hub
• Network topologies: mesh All of the devices on the network are interconnected with one another.
• MAC address Media Access Control: Each unique piece of hardware on a network has this type of address.
• Packet Switching A method of transferring data by breaking it into small chunks called packets.
• Server A computer that holds data to be shared with other computers. A web server stores and shares websites.
• WWW World Wide Web: All the interlinked HTML pages that can be accessed over the Internet
• The internet Global communication network that allows computers to connect and exchange information
• ISP Internet Service Provider: Organisation that provides access to the internet
• Router Network hardware that moves data packets through the network
• Firewall Network security system that checks incoming and outgoing data deciding to allow or disallow the data from entering or leaving the network
• Hacking The act of gaining unauthorised access to a computer system and its data
• Malware Malicious software - intended to harm or disrupt a computer system
• Protocols Networks rely on these sets of rules to allow different devices to communicate with each other
• URL Uniform Resource Locator: web page addresses for example: https://www.quizlet.com
• IP address A number that uniquely identifies each computer or device connected to the Internet.
• IPv4 "The Internet Protocol version 4 is the dominant protocol for routing traffic on the Internet specifying ""to"" and ""from"" addresses using a dotted decimal such as ""122.45.255.0""."
• IPv6 "Internet Protocol version 6 provides a large number of new addresses to route Internet traffic using ""from"" and ""to"" addresses written as colon-hexadecimal notation such as ""fe80::42:acff:feaa:1bf0""."
• SMTP Simple Mail Transfer Protocol: enables sending emails from a client to a server or between servers.
• POP3 Post Office Protocol 3: messages are deleted from the server after they are opened
• IMAP Internet Message Access Protocol: messages left on server retrieved from multiple devices
• FTP File Transfer Protocol: used to move files and folders over a network or the Internet.
• HTTP (Hypertext Transfer Protocol) The protocol used for transmitting web pages over the Internet
• HTTPS (Hypertext Transfer Protocol Secure) An encrypted version of HTTP.
• TCP (Transmission Control Protocol) Provides reliable ordered and error-checked delivery of a stream of packets on the internet. TCP is linked with IP and usually seen as TCP/IP
• IP internet Protocol
• TCP/IP Model A four-layer data communication model; Application - Transport - Internet - Link
• Network Switch
• Application layer encodes/decodes the message into a form that is understood by the sender and the recipient devices using protocols like HTTP file transfer protocol (FTP) and SMTP
• Transport layer breaks down the message into small pieces called packets. Each packet is given a packet number and the total number of packets. The recipient uses this information to assemble the packets in the correct order. It also allows the recipient to see if there are any missing packets.
• Internet layer - adds the sender’s IP address and that of the recipient. The network then knows where to send the message and where it came from. This is sometimes called the network layer.
• Link layer enables the physical transfer of packets between nodes on a network and between one network and another.