A public library provides services to the general public. If the library is part of a countywide library system, citizens with an active library card from around that county can use the library branches associated with the library system. A library can serve only their city, however, if they are not a member of the county public library system. Much of the materials located within a public library are available for borrowing. The library staff decides upon the number of items patrons are allowed to borrow, as well as the details of borrowing time allotted. Typically, libraries issue library cards to community members wishing to borrow books. Often visitors to a city are able to obtain a public library card.