Winsock. "Isn't that one of those tube-like flags that tell which way the wind is blowing?" Actually, that's a "windsock," which was first used by airline pilots to tell how fast and what direction the wind was blowing.
Winsock is actually short "Windows sockets," which are files that allow Windows programs to connect to the Internet and other computers. Technically, Winsock is an "Application Programming Interface (API)," that developers use to make their programs network-enabled. 16-bit applications use a file called WINSOCK.DLL and 32-bit applications use a file called WSOCK32.DLL. Both of these files are libraries of networking functions (based on TCP/IP), but they can differ from computer to computer, depending on the vendor. If you use Windows, you probably use Winsock on a regular basis. Fortunately, unless you're a Windows programmer, you don't have to understand exactly how it works.