TCP vs UDP (transmission control protocol) TCP is a protocol that allows devices to communicate reliably over a network. It ensures that data reaches the destination correctly and in the right order even if parts of the network are slow and unreliable example like when using tcp cat sends its food to another cat while sending she is ver carfull she wraps the food nicely and label it sends it and waits for the other cat to confirm it arrived if there is something missing she resends it so tcp is