Production Companies

A production company is crucial for a film to be made. The producer(s) is the person (or group of people) who pull together all the aspects that make a film, developing the project until the movie is complete. This includes finding all of the right ingredients for a great film- a script, financial investors, the right director, a cast, hiring equipment, a production team (including camera staff, makeup, costume etc), managing the budget and finding a company to distribute the film when it's finished.
They can be broken down into Major and Minor production companies. The major companies are in control of the entire production process (they make the films and distribute them). Minor companies would not necessarily have enough money or credibility to distribute their film at a high level.
Some companies (like NBC Universal and Warner Bros Entertainment) make films of many genres have made some great Thrillers, such as 'Jaws' (a Universal picture) and 'Gothika' (part produced by Warner Bros).
Some production companies specialise in Thriller films, such as Dark Castle Entertainment (who have produced films such as 'House of Wax', 'Orphan', 'The Reaping' and 'Ghost Ship'.