Multitasking is the ability of the operating system to manage the execution of more than one application at a time. For the programmer, this includes the ability to multitask your own programs.

The OS/2 operating system supports two forms of multitasking for programs. An application can start other programs that will execute concurrently with the application. These programs can be a new copy of the application, a related program that is designed to work with the application, or an unrelated program. The operating system provides functions to communicate with and control the programs started by the application.

The OS/2 operating system also enables applications to run multiple threads of execution within the same application; separate activities can be multitasked within the application. An example of this is dispatching a separate subroutine to load a file and having the subroutine execute at the same time the main routine continues to monitor and respond to user input.