Remapping Keys
The Galaxy Watch 4 comes with two buttons present on the right side of the watch.
The first one is the home button, single tapping navigates you to the home and double-tapping takes you to the most recent app. The second key is the back button for navigating to the previous screen
Well, remapping keys allows setting custom tasks of your choice. To add custom tasks, Go to Settings > Advanced features > Customize Keys.
On customize keys option, you can set custom actions to trigger on-button interaction. For example, you can open up any app shortcut, Wake up Bixby, power off the menu, navigate the previous screen, show recent apps, and more.