Do I owe federal taxes, if I chose to be exempt from them in my w4?

I recently got, a new job. It said that I could be exempt from federal taxes , if I met the qualifications. I had a tax refund, the last year and expect to have one this year too. I exempt it from my federal taxes on my W-4, does that mean I have to pay federal taxes, when tax season comes around, or are they simply just waved.  And just some more information about me, I'm single, I live with someone, and have no dependence.