What does this mean? I have a 97 240 sx se. Does my car have this?

 

Since you're new I won't flame ya... or maybe it's just because you're a girl. Anyways...

this is an LSD:
http://auto.howstuffworks.com/differential9.htm

this might or might not be on your car demending on the options. Do a search in the forum for "do I have LSD" and you'll find ways to determine it. Easiest is to look for a orange sticker on the diff cover (the large metal case in the center of the rear wheels when looking under the car from the rear bumper)