Switching programs or applications on the fly in multi-tasking operating systems means the ability to switch between native and/or emulated programs or applications that are still running and running in parallel while performing their tasks or processes, but without pausing, freezing, or delaying any, or other unwanted events.
The phrase is used to mean: In the automotive industry, the term refers to the circumstance of performing certain operations while a vehicle is driven by the engine and moving.
In multitasking computing an operating system can handle several programs, both native applications or emulated software, that are running independent, parallel, together in the same time in the same device, using separated or shared resources and/or data, executing their tasks separately or together, while a user can switch on the fly between them or groups of them to use obtained effects or supervise purposes, without waste of time or waste of performance.
[3] In restaurants, cafes, banquet halls, and other places involved in the preparation of food, the term is used to indicate that an order needs to be made right away.
[4][5][6] This is often because a previously-served dish is inedible, because a waiter has made a mistake or delayed, or because a guest has to leave promptly.
[7] In ice hockey, it is both legal and common for teams to make line changes (player substitutions) when the puck is in play.