How much interest do you get charged for loaning money for college?

I am so confused right now. You get charged interest if you loan money to pay for college right? But the interests does not start until you graduate from college right? So even someone like a neurosurgeon who is in school for a long time will not have interest until they finish their grad school or residency?

How much exactly is the interest? I can not imagine the amount of interest someone like a aspiring doctor who earned no scholarships and has a poor family would have?

bump

Interest is charged on all college loans. If you qualify for subsidized federal loans the government pays the interest while you are in school. Otherwise the interest accrues and is added to your loan balance after you leave school.

Interest rates range from 3% to 9%.