Transfer of control (program) - used to modify the Program counter.
  Branches - conditional or unconditional (relative).

  Jumps - conditional or unconditional (absolute).

    Many CPU designers use jumps and branches to be the same thing.
      Particular cpu design may have only jumps, but jumps may be 
      close, far, relative, absolute, conditional and unconditional.
  
  Function - transfers execution to a sub-section of program.
    Pair of instructions.
      Call - stores current PC in the stack and inserts a new value
        specified in the operand into the PC.

      Return - retrieves the orginal value from the stack.

      Simulated for IBM 360 with standard linkage - programmer provides
      stack function.