What are savings bonds and how do they work?

I recently received a $25.00 savings bond. I've never had one given to me before, so I'm not sure what it is. How does it work? Do I just keep the bond until I'm ready to use it for something such as college? Do I have to pay any money for it? I'm very confused…if someone could help me, that'd be great. Thanks!
I think the U.S. savings bond is worth $50.

a bond is like a savings account but with no monthly statement. each month the bond increases in value from interest that accrues/builds. the bond matures in 30 years from the date of the bond which means that after that time the bond does not grow in value anymore. you can cash it at any bank and get the money, preferably the bank you conduct business with. if you cash it within the first 5 years you pay a penalty. the penalty is that the last three months of interest that accrued will be taken away before youre given the cash.

i assume it is a us savings bond.