From Wikipedia
A handle is a particular kind of smart pointer. Handles are used when an application references blocks of memory or objects managed by another system, such as a database or an operating system. While a pointer literally contains the address of the item to which it refers, a handle is an abstract reference controlled by a separate system; its opacity allows the referent to be relocated in memory by the system without invalidating the handle — impossible with pointers. The extra layer of indirection also increases the control the managing system has over operations performed on the referent (see information hiding, encapsulation).
