Stage previews?

I just bought tickets to a stage play that stars some of my favorite A-list screen stars. However, the date I chose falls into the "preview" window and the "official" opening isn't until the next day (which I hadn't realized when I made the purchase). What's the difference between preview and official dates? Will I get to see my favorite stars at this "preview" performance? I like stage shows, but I must admit that I don't know many of the technicalities, and also, I'm mainly attending this specific play for the privilege of watching my favorite A-list actors perform live.

Stage previews?paramount theater

You've gotten great answers already. My only add is that generally preview tickets are cheaper and that's why I buy those. When you have a friend in the show you can even see these shows for free. I've never been disappointed by a preview performance, it's like going to their real opening night because many times it's the first time they run the show with full dress, sets, makeup, lighting, etc. It's as fresh for you as it is for them and sometimes a more exhilarating performance than opening night :-)

Like the others said, the stars should be there. This first time with all the costumes, etc. is important for them.

Have a great night!

Stage previews?theatre opera theater

Previews are like dress rehearsals with an audience. I think you will see your favs.
During previews the cast and crew are still testing their material on audiences and can still make changes if they need to. Since you are going to the preview the day before it opens their shouldn't be any changes between what you see and the official run of the show. Unless someone calls in sick (which can happen on official dates as well) you will definitely see your favorite stars. It's their dress rehearsal and their last chance to run the show before the press reviews it.

Have fun!
You will get to see almost the exact same show as the opening night show. "Previews" are, to put it simply, dress rehearsals with benefits. The actors will be their, the show will be amazing, and I guarantee you won't be able to tell a difference between the show you went to and a later production. "Previews" really are only for the tech crew so maybe a light will be a different color, but that's about it.