In the TCP/IP protocol suite, TCP is the intermediate layer

between IP below it, and an application above it. Using TCP,

applications on networked hosts can establish reliable

connections to one another. The protocol guarantees in-order

delivery of data from the sender to the receiver

Streams of data called segments are used by TCP peers to

speak to each other. The segments can be quite large, so TCP

breaks up the segments into smaller units of data. These units

are encapsulated in the TCP packet that is passed to the IP

protocol. Each unit of data is assigned a sequence number,

which becomes part of the TCP packet. At the receiving end, the

TCP module uses the sequence numbers in the packet to

reconstruct the user data in the correct order.