If you want to learn about networking protocols in a simple way, then, you're in the right place.
In this article, you're going to learn about three(3) important things that help computers communicate with each other:
Transmission Control Protocol (TCP)
UDP (User Datagram Protocol)
HTTP (HyperText Transfer Protocol)
These may sound like big, scary words, but don't worry!
I'll explain them in simple words.
By the end of this article, you'll understand the differences between TCP and UDP, the role each plays in networking, and how HTTP uses them.
As you may already be aware, Networking refers to the practice of connecting computers and other devices to share resources, exchange data, and communicate with each other.
Think of it as creating a web of connections that lets different devices talk to each other, just like how people use phones to talk to their friends.
What are Networking Protocols?
Before we dive into TCP, UDP, and HTTP, let's understand what a protocol is.
In simple words, a protocol is a set of rules that helps computers communicate. Think of it like a language that both computers understand. Just like we follow rules to play a game or speak a language, computers follow protocols to share information.
What is TCP?
TCP stands for Transmission Control Protocol. It is one of the most important protocols in networking.
Let's see what makes TCP special.
TCP is Reliable and Connection-Oriented
Reliable: This means that TCP makes sure that the information sent from one computer reaches the other computer correctly. If any data gets lost or messed up along the way, TCP fixes it.
Connection-Oriented: This means that before sending any data, TCP makes a connection between the two computers. It's like making a phone call: you dial the number, wait for the other person to answer, and then start talking.
How TCP Works
Handshake: TCP starts by doing a "handshake." This is like when you meet someone and shake hands to say "hello". The two computers agree to start talking.
Data Transfer: Once the connection is made, TCP sends the data. It breaks the data into small pieces called packets. Each packet has a number, so they arrive in the correct order.
Acknowledgement: The receiving computer sends a message back saying it got each packet. If a packet is missing or messed up, TCP resends it.
Closing: After all the data is sent and received correctly, the two computers say goodbye and close the connection.
Example of TCP
Imagine you are sending a letter to a friend. TCP is like making sure the letter is delivered safely, and your friend sends you a thank-you note to say they got it.
What is UDP?
UDP stands for User Datagram Protocol. It is another important protocol in networking, but it works differently from TCP.
UDP is Unreliable and Connectionless
Unreliable: This means that UDP doesn't check if the information sent from one computer reaches the other computer correctly. If any data gets lost or messed up along the way, UDP doesn't fix it.
Connectionless: This means that UDP doesn't make a connection before sending data. It's like sending a message in a bottle: you throw it into the sea and hope it reaches the other side.
How UDP Works
No Handshake: UDP doesn't start with a handshake. It just sends the data right away.
Data Transfer: UDP sends the data in small pieces called packets. These packets might arrive out of order, or some might not arrive at all.
No Acknowledgment: The receiving computer doesn't send a message back saying it got the packets. If a packet is missing or messed up, UDP doesn't resend it.
Example of UDP
Imagine you are throwing a paper aeroplane at a friend. UDP is like hoping the aeroplane reaches your friend, but if it falls in the water or gets lost, you don't know about it.
Differences Between TCP and UDP
Let's summarize the main differences between TCP and UDP:
Reliability: TCP is reliable because it checks if the data is received correctly. UDP is unreliable because it doesn't check.
Connection: TCP makes a connection before sending data. UDP doesn't make a connection.
Speed: TCP is slower because it makes sure everything is correct. UDP is faster because it doesn't check for errors.
What is HTTP?
HTTP stands for HyperText Transfer Protocol. It is a protocol used by web browsers and servers to communicate. When you visit a website, your browser uses HTTP to get the web pages.
How HTTP Uses TCP
HTTP uses TCP because it needs to make sure that the web pages are received correctly.
Let's see how HTTP and TCP work together:
HTTP Request: When you type a website address and hit enter, your browser sends an HTTP request to the server. This request asks for the web page.
TCP Handshake: Before the HTTP request is sent, TCP makes a connection between your browser (client) and the server. They do a handshake to say hello.
Data Transfer: The server sends the web page data back to your browser using TCP. The data is broken into packets, and TCP makes sure all the packets arrive correctly.
HTTP Response: Your browser receives the data and shows you the web page. If any packets are missing or messed up, TCP resends them.
Why HTTP Uses TCP
HTTP uses TCP because it needs reliability. When you visit a website, you want to make sure you get the whole web page, not just parts of it. TCP makes sure all the data is received correctly, so you can see the complete web page.
Putting It All Together
Let's review what we've learned about TCP, UDP, and HTTP:
TCP: This is a reliable, connection-oriented protocol that makes sure data is received correctly. It's like sending a letter with a thank-you note to confirm delivery.
UDP: This is an unreliable, connectionless protocol that doesn't check if data is received correctly. It's like throwing a paper aeroplane and hoping it reaches the other side.
HTTP: This is a protocol used by web browsers to get web pages. It uses TCP to make sure the web pages are received correctly.
More About TCP
Now that we know the basics of TCP, let's dive a bit deeper. TCP is used for many things on the internet, not just web pages.
Uses of TCP
Web Browsing: As we learned, HTTP uses TCP to make sure web pages are received correctly.
Email: When you send or receive an email, TCP makes sure the email is delivered correctly.
File Transfer: When you download or upload a file, TCP ensures the file is transferred without errors.
How TCP Handles Errors
TCP has special ways to handle errors and make sure data is received correctly:
Checksums: Each packet has a special number called a checksum. This number helps the receiving computer check if the packet is correct. If the checksum doesn't match, the packet is resent.
Retransmission: If a packet is missing or messed up, TCP resends it. This makes sure all the data arrives correctly.
Sequence Numbers: Each packet has a sequence number. This helps the receiving computer put the packets in the correct order.
More About UDP
Now, let's learn a bit more about UDP. Even though UDP is unreliable, it is still very useful for certain things.
Uses of UDP
Live Streaming: When you watch a live video or listen to live music, UDP is often used. This is because speed is more important than reliability. If a few packets are missing, you might not even notice.
Online Gaming: Many online games use UDP. This is because games need to be fast, and a few missing packets usually don't matter.
Voice Calls: When you make a voice call over the internet, like with Skype or Zoom, UDP is often used. This is because real-time communication needs to be fast.
Why Use UDP?
UDP is used when speed is more important than reliability. Since UDP doesn't check for errors or make connections, it is faster than TCP. This makes it perfect for things like live streaming, online gaming, and voice calls.
More About HTTP
We've learned that HTTP uses TCP to get web pages. Now, let's learn more about how HTTP works and why it is important.
How HTTP Works
Client-Server Model: HTTP uses a client-server model. Your browser is the client, and the web server is the server. The client sends an HTTP request, and the server sends an HTTP response.
Stateless Protocol: HTTP is a stateless protocol. This means that each request and response is independent. The server doesn't remember previous requests. This makes HTTP simple and fast.
Methods: HTTP has different methods for different actions. The most common method is GET, which asks for a web page. Another common method is POST, which sends data to the server.
Importance of HTTP
HTTP is important because it is the foundation of the web. Without HTTP, we wouldn't be able to visit websites, watch videos, or do online shopping. HTTP makes it possible for browsers and servers to communicate and share information.
Comparing TCP and UDP with HTTP
Let's see how TCP and UDP work with HTTP:
HTTP and TCP: HTTP uses TCP because it needs reliability. Web pages need to be received correctly, and TCP makes sure that happens.
When to Use UDP: If speed is more important than reliability, like in live streaming or online gaming, UDP is used instead of TCP.
Examples in Real Life
Let's look at some real-life examples to understand TCP, UDP, and HTTP better:
Example 1: Visiting a Website
Type the Website Address: You type www.example.com in your browser and hit enter.
HTTP Request: Your browser sends an HTTP request to the server.
TCP Handshake: TCP makes a connection between your browser and the server.
Data Transfer: The server sends the webpage data using TCP.
HTTP Response: Your browser receives the data and shows you the web page.
Example 2: Watching a Live Video
Open the Video App: You open a live video app like YouTube.
UDP Data Transfer: The app uses UDP to stream the video. UDP sends the video data quickly.
Watch the Video: You watch the live video. If a few packets are missing, you might not even notice.
Example 3: Sending an Email
Compose the Email: You write an email and hit send.
TCP Connection: TCP makes a connection between your email client and the email server.
Data Transfer: TCP sends the email data to the server.
Email Sent: The email server receives the data and sends the email to the recipient.
Conclusion
Now you know the basics of TCP, UDP, and HTTP!
TCP is reliable and connection-oriented, making sure data is received correctly. UDP is unreliable and connectionless, focusing on speed. HTTP uses TCP to get web pages reliably.
Remember, TCP is like sending a letter with a thank-you note, UDP is like throwing a paper aeroplane, and HTTP is like the language browsers and servers use to share web pages.
Happy networking!