HTTP vs. TCP: What is the Distinction?
HTTP vs. TCP
Hypertext Transfer Protocol (HTTP) and Transmission Control Protocol (TCP) are both computer protocols involved in the transfer of data, but while they individually serve their own purpose, they have a close relationship.
Let’s break down what HTTP and TCP actually are, what sets them apart, and how they work as a pair.
What is HTTP?
HTTP is a request-response protocol that allows users to communicate data on the World Wide Web (WWW) and transfer hypertext. The protocol remains one of the primary means of using the Internet and provides users a way to interact with web resources such as HTML files by transmitting hypertext messages between clients (such as a web browser like Chrome) and a server. Essentially, it’s used to load web pages using hypertext links.
It’s the backbone of the WWW and it defines the format of messages through which web browsers and web servers communicate. It also defines how a web browser should respond to a specific web request. It’s a stateless protocol which means no session information from previous requests is retained by the receiver. However, while the core of HTTP itself is stateless, it’s not session less, as HTTP cookies allow the use of stateful sessions.
HTTP is located at Layer 7 (the Application Layer) of the Open Systems Interconnection Model (OSI Model) and works similarly to other application services like FTP as it transfers data using a TCP/IP connection.
What is TCP?
TCP, short for Transmission Control Protocol, is a communication standard that enables application programs and computing devices to exchange data and/or messages over networks. It is included within the standards defined by the Internet Engineering Task Force (IETF) and is a stateful protocol.
This protocol defines how to establish and maintain a network connection through which data is then exchanged. It also determines how to break the application data into packets that networks can transfer and ensures end-to-end data delivery. TCP transmission is reliable, secure, and guarantees the integrity of data sent over a network, regardless of the amount.
TCP is at Layer 4 (the Transport Layer) of the OSI Model and works with the Internet Protocol (IP). IP is a principal communications protocol that dictates how data should be sent over the Internet from one network to the next.
Together, TCP and IP are the basic standards that define the rules of the Internet and are the most widely used protocols within the Internet protocol suite. However, many major applications rely on TCP such as HTTP, FTP, email, and remote administration.
The Main Differences Between HTTP and TCP
- HTTP typically uses port 80 – this is the port that the server “listens to” or expects to receive from a Web client. TCP doesn’t require a port to do its job.
- HTTP is faster in comparison to TCP as it operates at a higher speed and performs the process immediately. TCP is relatively slower.
- TCP tells the destination computer which application should receive data and ensures the proper delivery of said data, whereas HTTP is used to search and find the desired documents on the Internet.
- TCP contains information about what data has or has not been received yet, while HTTP contains specific instructions on how to read and process the data once it’s received.
- TCP manages the data stream, whereas HTTP describes what the data in the stream contains.
- TCP operates as a three-way communication protocol, while HTTP is a single-way protocol.
How HTTP and TCP Work as a Pair
In the case of HTTP, before a client and server can exchange an HTTP request/response, they must establish a TCP connection first. Therefore, HTTP relies on the TCP standard in order to successfully do its job.