How do you see what apps are open is there a task manager?

[nokia4life]

Forgive me its been more than 4 years since I last used WM is there a way to tell if an app is closed how is this managed? I go into a app then I am back at the home screen with the tiles but how do i see if prev apps are still open thanks.

 

[plandyman]

Just hold down the back button

 

[nokia4life]

that did it thanks again plandyman......