What are W-2 Exemption/Allowances?

I'm correcting my submitted college FAFSA information because I just got my W-2 papers , and noticed that under Exemptions/Allowances on my W-2 it says "Federal: 2". I don't have any kids or anything, and I claim myself as a dependent. Shouldn't this number be 0? I made $16,724 and the Federal Income Tax withheld (box 2) says $796.95.