My Nikon D5000 is taking two pictures at once?

My Nikon D5000 is taking two pictures at once. It doesn't show both on my camera playback, but once i import the photos, there's the normal one, and then one slightly edited. I'm not sure what mode or setting it is on that makes it do this, but if anyone knows how to turn it off, please tell me!

Are you set to take a jpeg and RAW files at the same time? I'm not familiar with amateur cameras but the pro ones can be set to do that. Look at your camera preferences to see where you can change that if it exists on your camera.

It's taking JPEG and RAW at the same time. RAW is a format which you can recover much lighting/shadow detail, most people don't use it unless you are a professional. Just change the setting from RAW+JPEG fine to JPEG fine

Ouch… You really Really need to read your manual!