TCP has an eleven-field header that holds the values that keep track of the conversation, as shown in the following diagram:

TCP uses the field values to monitor communication. TCP will indicate that the end device has successfully received all of the data. If there is trouble during the data transport, TCP will alert other hosts of any missing segments.

Next, we'll take a look at each of the header fields so that you have a better understanding of how TCP is able to provide reliable communication between hosts.