4 different types of opening sequences

Discrete Title Sequence:

Is like a mini film before the film and helps to get the audience into the mood of the film but not tell you what the film is about. It can give you an idea of the tone and the genre of the movie. A ‘discrete’ opening sequence also is often animated and includes a lot of editing work. For example, Se7en or The girl with the dragon tattoo.

Traditional: 

In this type of title sequence, films use sound and font to create the mood of the film.
For example Drive by Nicolas Winding Refn

Straight into a film:

A film, that goes straight into the story and doesn’t has an extra title sequence. A very good example of this is the title sequence of Wes Craven’s Scream. There are no titles at all and the film starts directly with then action of the opening scene. This type of title sequence is far less commonplace and is more likely to be seen in action or horror.

Stylised opening sequence:

A stylised title sequence is a combination of straight into it and discrete. The opening of the film starts straight into the action and then followed by a ‘discrete’ title sequence. The best and most famous example for that are the James Bond openings. This type of opening is often used in stylish action films such as Casino Royale or Mesrine.