i feel like every time i fill out a w-4, i fill it out a bit differently.

So when I was working full time for this short-term contract position, i had the following taxes taken out: Fed Withholding, Fed Med/EE, Fed OASDI/EE, and my state withholding tax.

Now I am working part-time (or maybe more like quarter-time) and I only have two tax categories taken out: Social Security tax and Medicare Tax.

i'm a bit confused. am i supposed to have more taken out?

and what's with the different terminology?
double checked and i DID fill out the same number of exemptions for both jobs....

i'm just curious now about the different terminology and why there are less tax categories in my current job- in contrast with my 1st job?