Why the difference in rates from interest to APR. I was approved for 3.7 interest but my APR is 4.7?

Why the difference in rates from interest to APR. I was approved for 3.7 interest but my APR is 4.7?
Added (1). Why the difference in rates from interest to APR. I was approved for 3.75% interest but my APR is 4.79%? Purchase at $347,500 - 30 year fixed FHA, my credit =750, 3.5% downpmt. Sellers have agreed to pay closing costs. Condo in Arlington, VA.
Added (2). Why the difference in rates from interest to APR. I was approved for 3.75% interest but my APR is 4.79%? Purchase at $347,500 - 30 year fixed FHA, my credit =750, 3.5% downpmt. Sellers have agreed to pay closing costs. Condo in Arlington, VA. No points.
Added (3). Sorry, this is for mortgage loan. Sorry on updates, i thought each update would replace the one before. :)
Added (4). In your opinion, is this a good deal?
Added (5). This who home purchasing thing is really making me physically ill. The stress and worries! :/
Added (6). No points upfront. Should I pay points? Doesn't that lower your interest? I plan on living here at least 8 years, until my daughter goes off to college.

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