What is TCP (Transmission Control Protocol)

How do devices communicate and exchange data on the web?

IP (Internet protocol) delivers information packets on the web from the source device to the target device and establishes the basis of the connection, but it does not sequence the packets or check for errors, TCP (Transmission Control Protocol) is needed for this.

TCP sends data unstructured as bytes, using sequenced numbers and acknowledgment messages.

If data is lost on the way from source to destination, TCP can retransmit data until a timeout condition occurs or delivery ends successfully. TCP can detect duplicate messages and weed them out.

If the transmission rate of the source device is higher than the destination device, TCP uses the data flow control mechanism and slows down its transfer.

It can communicate with upper layer protocols and applications that support TCP transmission information. The top layer protocols help TCP/IP to work.

3-Way Handshake

When sending data over TCP, there is a triple handshake between devices. First, the source device sends the “SYN” (synchronization) initial request packet to the target device to initiate the communication, then the target device sends the “SYN-ACK” packet to the source device for transaction acceptance. Finally, the source device confirms the transaction by sending the “ACK” (acknowledge) packet and the data is sent, this structure is called the triple handshake.

Source:

https://www.cloudflare.com/learning/ddos/glossary/tcp-ip/