Any wood shop needs a power sander, even if your wood shop is nothing more than a garage workbench. And as luck might have it, you need a couple different kinds depending on the kind of work you're doing.
The most common woodworking sanders are the belt sander, and the orbital pad sander.
Sander Orbital
A belt sander is a great tool for doing coarse shaping work. You can remove a LOT of material very quickly. You can equip your sander with a fine or coarse sanding belt, or any coarseness in between. But no matter how abrasive a belt you use, it's designed to remove a lot of material quickly.
Care should be used with a belt sander to make sure you don't remove too much material - it can't be put back.
Many of these kinds of sanders come with an attached dust catcher. A dust catcher does a fair job of keeping the mess down, but they only really catch a small percentage of the dust created.
An orbital pad sander - otherwise known simply as a pad sander, does a great job at more fine sanding jobs. It removes material a lot less aggressively than a belt sander does. A pad sender is great for removing thin layers of material such as paint, primer, or other finish coatings.
Many pad sanders have a built in dust catcher which only catchers a small amount of the dust created - but it's better than nothing.
A pad sander is also a superb tool for sanding a rough surface into a smooth as glass finish.
All pad sanders and belt sanders available on the market have a wide range of compatible sanding pads and belts of varying coarseness to meet the demands of any job.