In most cases, obtaining a federal student loan does not require a credit check or a cosigner. Since federal loans do not require a cosigner (i.e., a person that pledges that they will pay back the loan if you do not), you are responsible for repaying the loan yourself. However, if your parents take out a Direct Plus Loan, they will be responsible for repaying that loan themselves.
Direct Plus Loan (Federal)
If your parents decide to take out a Direct Plus Loan to help finance your education, they will be subject to a credit check, since they are not allowed to have an adverse credit history.
It is also important to note that this type of loan can not be later transferred to you, your parents solely are responsible for repaying the loan.
Student Loans That Need A CoSigner (Private)
If you decide to take out a private student loan, more than likely your parents will have to cosign it. The reason being either you have insufficient credit history and/or you are underage (under 18 years old).
Unlike a federal loan, which is funded by the federal government, private loans are made by a lender, such as a bank, credit union, state agency, or a school. Private loans also vary by lender and type of loan, so be sure that you understand the terms of your loan beforehand.