What is the purpose of a title sequence and film opening?

The purpose of a film opening is to give the viewer an idea of how the movie is going to be like, with the use of music and visuals the viewers can acknowledge the genre of the film and within those 2 minutes they can make the decision whether this film will be entertaining or not. For instance, in an action movie if the film starts off by showing high action visuals along with fast paced music this will immediately catch the audiences attention and make them intrigued, this will lead to the viewer having a positive experience when watching the movie making the film a success. Also with the use of a title sequence the audience are aware of who will be starring in the movie and they will notice who the main characters are, this is very important as the viewers will not then have to figure out who is who throughout the film leading them to be confused and overall not enjoy themselves. Furthermore by displaying the main characters the audience will have an idea of whether they will like the movie or not, for example by showing that a huge actor like Leonardo Dicaprio is starring in the film the audience will most likely think that the movie will be good as Leonardo Dicaprio has starred in many successful films and is also a worthy, and very long overdue, Oscar winner. Not only actors but institutions get credited too in the title sequence and by showing the audience a big institution like Warner Brothers are part of the film, this will instantly get the viewers approval as WB are a studio which have produced some of the most successful movies in the world. In concusion the title sequence is very important as it is meant to get the viewers attention and get them to be engaged in the film, by creating a good film opening it almost creates a suspending disbelief for the audience which will only lead to a positive experience when watching the movie.