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What is TCP?

When data travels across the internet, it doesn’t move as a continuous stream. Instead, it gets broken into small pieces called “packets.” These packets are sent separately, then reassembled at the receiving end. TCP stands for Transmission Control Protocol, and it’s the process that makes sure that packets are broken down and reassembled correctly. When combined with Internet Protocol, it is referred to as TCP/IP. 

TCP provides a consistent, reliable internet experience. Before any data moves between two devices, a connection must be established. As packets arrive, the receiving device sends confirmation back to the sending device. If any packets are missing or arrive corrupted, TCP sends a follow-up request. 

Nothing gets marked as delivered until it has all arrived quickly. 

The thoroughness of TCP/IP has a tradeoff: it takes time. All that back-and-forth checking and communicating leads to a slight slowing of your internet speed. Some applications are affected more than others. Loading a web page, sending an email, and downloading a file are all actions that prioritize accuracy over pace. However, things like video calls and online gaming need near-immediate data speed. For those settings, UDP is typically used instead.