Digital cinema is the continuation of the art and science of cinema using digital storage and display instead of film.
Note that digital cinema is distinct from high definition television which has different cultural and industrial origins.

In particular, digital film is not dependent on using television or HDTV standards, aspect ratios or frame rates.

Star Wars Episode I: The Phantom Menace was said to be the first digital movie which could be distributed to digital cinemas electronically.

See also:

digital projector -
digital film post - production

Digital cinema companies:

Filmlight
Lucasfilm
Sony
Texas Instruments
and many more...

External links:

http://www.stageaccompany.com/news/itea/itea.html
http://www - apparitions.ucsd.edu/~manovich/text/digital - cinema.html