A general register is a register whose usage is determined by the programmer, rather than being predefined as with dedicated registers such as the stack pointer. On an Intel CPU such as the 486 or Pentium, the 16-bit general registers are ax, bx, cx, dx, si, di, and bp; the 32-bit general registers are eax, ebx, ecx, edx, esi, edi, and ebp.
Global scope describes the visibility of variables that are defined outside any function; such variables can be accessed by code in any function. It also describes the visibility of functions that are defined outside any class.