Our brain rewards us for some activities we so and it does this by releasing dopamine into the reward centers in our brain. Addiction comes in when more and more dopamine has to be released to give a reward. The pleasure you feel after an action is as a result of dopamine release.
This is not a detailed info but should be enough for a basic understanding.
The second part of this blog contains much more. Pass by today for it.
I'd be expecting it
So would I. I need more information on this topic