To incorporate is to include or integrate a part into the whole. Incorporate is a more active version of the word "include"; if you incorporate, you are adding something to the mix.
In the business world, to incorporate is a legal process. In other usages, the word incorporate really just means to include something or work something into whatever was already existing. You could incorporate your new roommate's furniture into the decor of your apartment, but you may not find a way to incorporate her cat's litter box.