The two players can also play online while using split screen. This game mode is normally exclusive to the Xbox 360 version of Left 4 Dead and Left 4 Dead 2, but may be accessed in the PC versions if you have a controller for the second player and modify some files.
Serial memory processing - Wikipedia. Serial memory processing is the act of attending to and processing one item at a time. This is usually contrasted against parallel memory processing, which is the act of attending to and processing all items simultaneously. https://en.wikipedia.org/wiki/Serial_memory_processing
centralized processing. Processing performed in one computer or in a cluster of coupled computers in a single location. Access to the computer is via dumb terminals, which send only input and receive output or smart terminals, which add screen formatting. All data processing is performed in the central computer. Centralized processing evolved from the first computers in the 1950s, which were stand-alone with all input and output devices in the same room.