An incrementing of the reference count of an object. An object with a positive reference count is not freed. (A newly created object has a reference count of one.) Drivers can ensure the persistence of an object beyond the present scope by retaining it. Many APIs automatically execute a retain on the caller’s behalf, particularly APIs used to create or gain access to objects. Retains and releases must be carefully balanced; too many retains will result in wired memory leak. Compare release.