here in Egypt when you go to the cinema it means that you will watch movie on a screen, but if you will go to the theater it means that you will meet the actors face to face and watch them when they perform the show

I rarely hear "cinema" used on the west coast or mountain states in the US. Movie theater is more common, but they mean the same thing in general. When I hear cinema I think of the fancy billboard style movie theater with the vertical sign and lots of lights showing the playbill. Otherwise theater is a more broad word that can mean movies or several other performance styles as others mentioned.

Like Kareem said, "theater" has a strong association with live performance - actors on a stage. Here in the states (U.S.) both theater and cinema can mean you are going to see a movie on a big screen. "Theater" is often combined with "movie" to make Movie Theater. "I'm going to the movie theater" "I'm going to the cinema" Both can mean the same thing.

I see，thank you soooo much for your explanation！

Interesting to see Matthew's answer about 'US' English using them for both. In the UK we use the same definitions as Kareem has used, Theater (which in the UK is 'Theatre') is live and Cinema is a film. I do feel somewhat sorry for people who get confused by the difference between 'US' and 'UK' English for both spelling and definition. However BOTH are correct, depending upon where you are.