Just like books there are different genres of movies. The primary reason for watching movies is definitely entertainment but what entertains each of us may differ in subject matter and content. Some of the components of a movie like the screenplay, the dialogues, the plot and acting determine if the movie is watchable or not. To find out why people watch movies we need to understand first that people do not like to watch all sorts of movies. Some movies win accolades and Academy awards whereas some fade into oblivion. The movies have only one goal and that is to entertain us.
Human brain seeks entertainment and wants to be provoked into thinking or feeling. People just don’t watch movies but they empathize with the protagonists and feel their pain, remorse and laugh when they laugh. We can identify a part of ourselves in them and that is the reason why movies interest us. Emotions that we never knew existed come to the fore when we watch a well made movie. Humans can think individually and they need food for thought. Movies make us think and feel at the same time and that is why we watch movies.
A larger than life experience is also prized by us and it can be provided only by movies. Both books and movies help us escape from our personal problems and the daily drudgery we go through. It is a break from the routine and provides us with respite for a few hours at least. What we cannot experience in real life we can do through the movies. This is exactly why we are ready to believe the most absurd situations and fantasies made to seem real on screen. While engrossed in a movie we identify ourselves with the hero or heroine and escape into a world of their dreams.