This illustration shows client devices and servers configured in an X formation, with a smartphone and desktop computer forming the left side of the X and two servers forming the right side of the X. The smartphone and computer are both labeled "Client," while the two servers are both labeled "Origin server." In the center of the X is a server labeled "Proxy server." Each of the four components of the X-the smartphone, the computer, and the two origin servers-has a blue arrow pointing from it to the proxy server, labeled "HTTP request," and a blue arrow pointing to it from the proxy server, labeled "HTTP response."