In a computer a "bus" is an electrical channel for getting information and commands in and around the computer. It is the way the central microprocessor running the computer gets its information and commands to the various peripheral devices or device controllers, such as video cards, hard disk cards, etc.
This is an "information only" category. If you have an article or other important information you can submit to any of the subcategories of Hardware and it will be placed in the category for you.
If you have a product, then submit to the proper category in Hardware as this is not where it belongs.