How are federal subsidized and unsubsidized loans different?

Subsidized loans have a fixed interest rate, and unsubsidized loans do not.
Subsidized loans accrue interest while the student is in school, and unsubsidized loans do not.
Subsidized loans have a six-month grace period after graduation, and unsubsidized loans do not.
Subsidized loans require a student to show financial need, and unsubsidized loans do not.