This is a great definition of 'handle' I found on WikiBooks
HANDLE
HANDLE data types are some of the most important data objects in Win32 programming, and also some of the hardest for new programmers to understand. Inside the kernel, Windows maintains a table of all the different objects that the kernel is responsible for. Windows, buttons, icons, mouse pointers, menus, and so on, all get an entry in the table, and each entry is assigned a unique identifier known as a HANDLE. If you want to pick a particular entry out of that table, you need to give Windows the HANDLE value, and Windows will return the corresponding table entry.
HANDLEs are defined as being unsigned 32-bit quantities in <windows.h>, but HANDLEs should never be used like integers. They are unique identifiers, and if you edit them, or use them in arithmetic, then they can never be used to get the table entry that they correspond to. In other words, HANDLEs should be stored, but they should never be changed by the programmer.
HANDLEs are generally prefixed with an "h". Below are a few special handles that are worth discussing: A handle is actully a pointer to a pointer to a memory location.Handles are unsigned integers that Windows uses internally to keep track of objects in memory. Windows moves objects like memory blocks in memory to make room, if the object is moved in memory, the handles table is updated.
