Technically it is a tool to edit graphics of the raster screen. It manipulates the pixels of the resolution and changes its location as user specified. It was developed in 1988 by Thomas and John Knoll. The software helps raster images created in multiple layers. Its also capable to edit text and create 3D graphics and video.
Adobe continues to show its creative minds. On its anniversary it releases a short video comprising creations done using Photoshop worldwide by various artists. -- The music playing is "Dream On" by Aerosmith to signify its continued success and not stopping. Artists from around the world submitted their PSD files to Adobe. They then created a film in Photoshop using the images layer by layer. The result you see is a treat for your eyes. You cannot imagine how beautiful colors can be. The video showcased pretty piece of art and what impossible things can be achieved using Photoshop's animation.
The company wants to show the hard work that goes in creating such beautiful software. It will post a timeline describing it's milestones for past 25 years from a scratch to artist's favorite designing tool. Thomas Knoll will do AMA on Reddit at 11 a.m.