What is this and how do I use it

I am very confused as to what this is. I would like to know what it is and if possible please leave a link on how to use it.
whatisthis

That is a ProximityPrompt.

There are plenty of resources you can use to learn about them:

https://www.roblox.com/games/6074153281/Dungeon-Delve

that is proximityprompt if you didnt know