Ref - Network Layers

HTTP vs HTTPS vs TCP vs TLS vs UDP

Application Layer: (Layer 7) - HTTP(Hypertext Transfer Protocol): Stateless Request Response Cycle. - HTTPS: Secure HTTP. - SMTP: Email Transfer Protocol. - FTP etc...

Transport Layer: (Layer 4) - TCP (Transmission Control): Reliability > Performance. - TLS (Transport Layer Security): Secure TCP. - UDP (User Datagram Protocol): Performance > Reliability. Some applications (eg. video streaming) might use this network layer (UDP protocol) directly (skipping the application layer).

Network Layer: (Layer 3) - IP (Internet Protocol): Transfer bytes. Unreliable.