Difference between Requested Cruising Level and Flight Level???

[futr-kofeshop-dweler]

Hello kiddies, this is the world most expensive assistant in training, with a quick question, no not about money / working conditions / or who is dipping who's pen in the company ink! This question is about ATC stuff, and it's area-ish stuff so here's the million dollar question:

Is there a difference between a crusing level and a flight level? I'm asking because we're looking at filed flight plans, and it seems pilots have to file not only a requested flight level, but also a requested cruising level... So what's the diff??? Any???

Thanks in advance for any light shed, and hopefully this ATC question can be dealt with quick, so we can get to more important stuff like when is DCA gonna give me 70,000 dhs a month, plus free medical???