A loan is granted for a specific time period. Generally commercial banks grant short-term loans. But term loans, that are loan for more than a year, may also be granted. Loans are generally granted against the security of certain assets. An advance is a credit facility provided by the bank to its customers.
It differs from loan in the sense that loans may be granted for a longer period but advances are normally granted for a short period of time. The rate of interest charged on advance varies from bank to bank.