Some loans accrue interest while you are in school and others begin after you graduate. Subsidized vs. Unsubsidized loans.
At our school we had a certain amount deposited to our bank account at the beginning of each quarter that covered tuition and books (we never saw this money) and the rest for living expenses. So 3 or 4 disbursements per year. It may vary depending on the school. They also offered an optional transition loan for when you graduate to cover moving and a couple months worth of expenses.