Alfred Hitchcock was well known for being "The master of suspense". Hitchcock directed many popular productions. These include "The Birds" and "Psycho" which are very popular for their tension and suspense building.
Hitchcock used many different methods to make the content of films as good as they are. One of these is "The McGuffin". The job of "The McGuffin" is to keep the plot, character, or situation rolling along. It draws the viewer into the story and drives the action. The McGuffin is often an object of high value, which everyone covets. It can be ambiguous, entirely undefined, or left open for the viewers imagination/interpretation. this is what can make a film tense.