Net pay is what you actually get to take home after paying all the taxes and dues on you by the company or the government. For example, your salary is $500 per week and the applicable tax is $80, after paying that tax you would get $420 as your net amount.
On the other hand, YTD amount is the total amount you have earned from the beginning of a year till the end day. This amount usually appears on an individual's pay stub, along with information about Medicare and Social Security withholdings and income tax payments.
