How do I close running apps on my Galaxy smart phone?

For older Galaxy phones, follow the steps below:

3.        Tap End next to an application to close it.

4.        To close all running applications, tap End all.

5.        Alternatively, press and hold the Home button and then slide left or right until the app is deleted.

or

1.        From Front Screen tap Apps button.
2.        Scroll left and tap Settings.
3.        Tap 'More' tab
4.        Application manager
5.        Running
6.        Select the application you wish to stop
7.        Force stop

For newer Galaxy phones, follow the steps below: 

1.        Go to Home Screen

2.        Tap left touch pad beside the home button

            If the device has an infinitiy screen (S8/S8+/Note8), then tap here:

3.       Swipe left or right the app you want to stop running

4.       Tap CLOSE ALL