You are a bit confused and the employer may be able to explain it better but here it is ...
On your paycheck there are the wages from the employer + the tips you reported (that you already have in your hand) which gave you the gross taxable income on the paycheck. On that gross federal/state taxes & your half of the FICA taxes are withheld. So the gross taxable income less the taxes that are withheld gives you the net paycheck amount. AND the employer pays their 1/2 of the FICA taxes on your gross income which is good for you. So in the end your spendable cash equals the net paycheck+ the tips you walked home with on the day you earned them.
