Video calling for the screen

Hi, I'm looking for to video call a friend of mine who lives far away but instead of videoing me i need to video my screen so we can work together. The only way i can see to do it so far is to record my screen and then send it to him but this really isn't an efficient use of time and effort. I would also need to be able to speak to him and hear him speaking, is there an app or something that does this.

Many thanks