NSHTTPCookie implements a singleton object (shared instance) that manages storage of cookies. Each cookie is represented by an instance of the
NSHTTPCookie class. As a rule, cookies are shared among all applications and are kept in sync across process boundaries. Session cookies (where the cookie object’s
session method returns
YES) are local to a single process and are not shared.
In macOS 10.9 and later and iOS 7 and later,
NSHTTPCookie is thread safe.