About some popular internet protocols

In this article i am discussing about some protocols used widely in web dev.

1. HTTP
2. HTTPS
3. FTP
4. SSH
5. IMAP
6. SMTP

SSH

• It will allow users to access files and control system in remote over internet.
• Data will be encrypted. So middle persons cannot see the actual data.
• It will maintain state of connection.
• As i mentioned in the first point one user can control other machine shell / command prompt with SSH.
• Format to use ssh <SYSTEM_USER_NAME>@<HOST_IP>.
• Default port number is 22.
• Generally developers will use SSH to access containers or servers. Example AWS EC2 cluster can be accessed by SSH, Digital ocean droplets can be accessed by SSH.
• Widely used encryption methods in SSH are AES and Blowfish.
• Refer this link to know more about how encryption works in SSH.

HTTP

• Hypertext transfer protocol allows us to send files like HTML, CSS, JS and image files etc.. between client and server.
• It is stateless. It won't maintain any state.
• Format to use http://<DOMAIN/IP>:PORT
• Default http port is 80
• It is oneway communication.

HTTPS

• HTTP has a drawback. Any one can read the data while transferring because data will be in plain format. To solve this problem we will use HTTPS. It will encrypt the data while transferring so man in middle can't see the actual data as it is encrypted.
• It is stateless. It won't maintain any state.
• Format to use https://<DOMAIN/IP>:PORT.
• Default http port is 443.
• It is also oneway communication.

HTTPS = HTTP + SSL

FTP

• File transfer protocol is used to share / upload files between to machines.
• Unlike HTTPS it is bi-directional
• Client can upload files in server and server also can do the same.
• It is outdated. People won't prefer to use this protocol in these days.
• Default port number is 21.
• Format to use in command prompt ftp <DOMAIN/IP>.
• It will maintain state of connection.

IMAP

• Internet Message Access Protocol is used to receive emails in internet.
• Default port number is 143.

SMTP

• Simple mail transfer protocol is used to send emails in internet.
• Default port number is 25.

Happy coding!