The Media Browser makes it easy to use your photos, movies, and other media in your iLife and iWork projects. For example, if you’re using Pages to write a letter, you can open the Media Browser in Pages to add a photo from your iPhoto library to the letter, without having to open iPhoto.
Most iLife and iWork applications provide a Media Browser so you can easily use photos, slideshows, music, movies, and other digital media across applications.