What module to install for Photo Album ?

The two most popular solutions are:

http://drupal.org/project/image
It contains most things that people usually need (categorizing in galleries, thumbnails and full images etc)

Also the "do it yourself" way, using a combination of modules:
http://drupal.org/project/imagefield
http://drupal.org/project/filefield
http://drupal.org/project/imageapi
http://drupal.org/project/imagecache (for thumbnails)
http://drupal.org/project/cck
http://drupal.org/project/views (for a gallery)
to set it up exactly the way you want. This will take some work and some reading.

Other solutions:

http://drupal.org/project/gallery
A "bridge" module for integrating the specialized Gallery2 script (not a Drupal module).

Also the simpler ones:
http://drupal.org/project/brilliant_gallery
or
http://drupal.org/project/photos

Read their project pages to get an idea.

Image
Image Gallery and for a cool display of photos lightbox2

nothing else.

not that of a simple way are the modules mentioned in the above comment. It depends on what you wish to do.