Hyper Text Transfer (HTTP) Protocol

• HTTP is used to access the data on the World Wide Web (www).
• It is is an application layer protocol.
• It is connectionless, media-independent, TCP/IP based, and stateless protocol.
• The HTTP protocol uses port 80 by default but it also can use other ports well.
• It transfers the data in the form of plain text, hypertext, audio, video, Html files, query results, etc.
• HTTP is similar to FTP in terms of transferring the files from one host to another host.
• But, HTTP is simpler than FTP because HTTP uses only one connection that is a data connection, in HTTP there is no control connection is used to transfer the files.
• HTTP is also similar to SMTP in terms of data transferred between the client and server.
• But, HTTP differs from SMTP in the way the messages are sent from the client to the server and from the server to the client.
• In HTTP messages are delivered immediately instead of stored and forward later happened in SMTP.
• It is further categorized as HTTP 1.0, HTTP 1.1, HTTP 2.0 and HTTP 3.0.

File Transfer Protocol (FTP)

• FTP is an application layer protocol.
• It is used to exchange files over the internet and enables the users to upload and download the files from the internet.
• It transfers both text and binary files over the Internet. But mainly used for transferring the web page files from their creator to the computer that acts as a server for other computers on the internet.
• It transfers the data more reliably and efficiently.
• FTP uses TCP at the transport layer.
• FTP is a connection-oriented protocol.
• FTP is an out-of-band protocol as data and control information flow over different connections.
• FTP creates two connections between the computers one connection for the commands and replies called control connection and a second connection for data transfers called data connection.
• FTP uses Port number 21 for the control connection and Port number 20 for the data connection
• FTP is built on a client-server model architecture using the control connection and data connection between the client and server.

Simple Mail Transfer Protocol (SMTP)

• SMTP is mainly used for sending emails efficiently and reliably over the internet.
• SMTP is a push protocol and uses TCP at the transport layer.
• SMTP uses persistent TCP connections, so it can send multiple emails at once.
• SMTP is a connection-oriented, stateless, and in-band protocol.
• SMTP uses port number 25.
• SMTP is a general set of interaction guidelines that allow the software to transmit electronic mail over the internet.
• It set up communication rules between servers and allows the exchange of emails between the users on the same or different computers.
• SMTP is a pure text-based protocol. It can only handle the messages containing 7 bit ASCII text and can not transfer other types of data like images, video, audio, etc.
• SMTP can not transfer executable files and binary objects.
• MIME extends the limited capabilities of email. It enables the users to send and receive graphics, audio files, video files, etc in the message.MIME was specially designed for SMTP.
• Sometimes SMTP Auth stands for SMTP Authentication has been provided for authentication purposes.