When a little one points to or gives you something they’re interested in they’re using JOINT ATTENTION! Words children hear during an interaction involving joint attention are strongly linked to their vocabulary development. For example, when a 12 month old draws his mother’s attention to a ball and the mother says,“yes, that’s a ball, do you want to play with the ball? Let’s throw the ball!” He has heard the word 3 times. This makes it much easier for him to learn and eventually say the word “ball”, because he’s now had experience with it!!

https://seemeandliz.com/what-is-joint-attention-and-why-is-it-necessary-for-language-development