This image uses various colored shapes to illustrate the way in which TCP segments are sent and received. We see first a white oval on top of a dark blue rectangle on top of a light blue square. The white oval is labeled "Process writes data." A blue arrow extends downward through the dark blue rectangle, labeled "Socket," and into the light blue square, labeled "TCP send buffer." From here a blue line extends horizontally to the right where we see the same three shapes in the same order, connecting one light blue square to the other. Along this blue line, we see two TCP segments traveling from left to right through a cloud representing a network, on their way to the second light blue square. This square is labeled "TCP receive buffer." A blue arrow extends upwards, through the dark blue rectangle similarly labeled "Socket," and into the white oval, labeled "Process reads data."