Apple Users

Running processes in background.

Swiping up quickly from the bottom of the screen will show you how many apps are actually still running and not shut down. To actually shut them down you have to flick them upwards again.

If they are frequently-used apps, that's also one way to switch between them, and to avoid them having to consume resources by starting up every time. But, like your safari pages, at the point I learned how to actually stop apps from running, it was quite a collection.