When I am in a game what does it mean when it says I can bind words letters, I may be wrong on this but I know there are brains on here

Can you give us some context for the question?
Is this a walkthrough saying this or the game.

Are you trying to remap your keyboard for a game?
In that case you might, for example, "bind" the spacebar with the command to jump -- so if you wanted to jump in the game you would use the spacebar.

Jenny, yes it is for the game and I do not understand it at all, it is for the Witcher 3

Like Jenny said, we still need more specifics. Where is this showing up in the game? Or is it a walkthrough?

Binding normally means "binding" a key on your keyboard to a specific action. But without more information it's hard to figure out what you mean.

Are you talking about something like this...

https://www.youtube.com/watch?v=Bmm8pOWvK14