These are the various programs that are currently running on the computer.

By taking turns with the Machine Cycle, modern computers can have several different programs running at once. This is called multi-tasking.

Each open application has to have some data stored in Main Memory, even if the application is on rest break and is just sitting there. Some programs (graphics programs are notorious for this) require a lot of the Main Memory space, and may not give it up even if they are shut down! Rather rude, actually!!