Switcher is a new feature introduced on the PS5 that allows you to quickly switch between the various games and apps saved on your console. Switcher can be found in the Control Centre and selecting it will bring up a list of the games you've played recently, including the one you're currently playing.
What is switcher on the PS5?
How to Use Game Switcher in PS5 :- Game Switcher is an application which helps you switch instantly between games and applications that you have been using recently.
How do you switch between apps on PS5?
From the home screen, select [Settings] > [System] > [Remote Play], and then turn on [Enable Remote Play]. To start Remote Play while your PS5 console is in rest mode, select [Settings] > [System] > [Power Saving] > [Features Available in Rest Mode].