Becoming familiar with your tools and the different situations in which they should be used are crucial to any DIY job. You might be confident you know how to sand a floor, but if you're going to use a power sander - or buy a new one - you want to choose the right one. They might all make a similar sound when they get going, but each is as different as a snowflake.
Here's the run down on the most common types of power sanders.
This is the one to choose when dealing with a large amount of material that you want scraped off and smoothed down. By using pulleys to revolve a belt of sandpaper around, the belt sander has the appearance of a miniature tank - and is more or less as powerful!
While the power of such a machine can be very useful, it pays to remember to be cautious - it can easily cause gouging if used improperly, or damage material that is too thin. Always be sure to go with the grain, and be aware that these machines won't be able to go into corners.
There's a pattern with power sanders. Just as the belt sander grinds a belt of sandpaper, so the disc sander uses - you guessed it - a disc-shaped piece of the material, in this case by spinning it in a circle.
Because of their ability to remove a lot of material quickly, disc sanders are typically used for metal sanding or for removing paint. Avoid using it to polish surfaces, however, as its speed and aggressiveness can easily leave scratches.
Random orbit sanders
There are a few features that make random orbit sanders something along the lines of a Jack-of-all-trades among sanders. These machines use sandpaper on a round sanding pad that vibrates and spins simultaneously, reducing marks. It may not remove material as quickly, but it'll sure leave a smooth surface at the end of it all.