Protocols

• IP: The intenet protocol usually abbreviated to IP, is a part of the system used for data communication between all Internet-connected computers and networks.
• TCP: TCP operates on top of IP, and working on top of IP, and is used to set up connections.
• TCP Port: A unique port for a specific service.
• SMTP: Works on top of TCP. Has port number 25 and is used for sending mail.
• FTP: Works on top of TCP. Has port number 21 and is used to send large files. Existed since 1971. File Transfer Protocol
• HTTP: Is the protocol for communication between a web browser and web server.
• HTTPS: Encrypted version of HTTP making it impossible to intercept the connection.
• HTTP REQUEST: Request from the browser to the web server.
• GET: http request type that is intended to retrieve information. (GET / index.html) (GET / image.jpg)
• POST: type http request that is meant to send information. (POST username = 'admin') (POST avatar.jpg)

The size of the prefix, in bits, is written after the oblique. This is called "slash notation". There is a total of 32 bits in IPv4 address space. For example, if a network has the address "192.0.2.0/24", the number "24" refers to how many bits are contained in the network. From this, the number of bits left for address space can be calculated. As all IPv4 networks have 32 bits, and each "section" of the address denoted by the decimal points contains eight bits, "192.0.2.0/24" leaves eight bits to contain host addresses. This is enough space for 256 host addresses. These host addresses are the IP addresses that are necessary to connect your machine to the Internet.

A network numbered "10.0.0.0/8" (which is one of those reserved for private use) is a network with eight bits of network prefix, denoted by "/8" after the oblique. The "8" denotes that there are 24 bits left over in the network to contain IPv4 host addresses:16,777,216 addresses to be exact.