How to repair wooden floorboards?

So I'm completely clueless about this and not even sure if this is the right sub for it (didn't find anything against it in the sidebar).

I have a floor with a few boards that are coming apart (a small slice chipped off and it's just coming off more and more) and was wondering if there was something I could do about it? I have no equipment whatsoever but am willing to buy something suitable for this, I'd just really like to have it look normal/stop it from coming apart further.

https://i.imgur.com/1atDIVK.jpg - This is how it looks like, I don't have the pieces that have come off of it unfortunately.

I'm moving out soon-ish and it's going to get really expensive if it looks like that.

Thanks in advance and sorry for not being able to provide more information about it.