Some definitions

A machine instruction is one of the fundamental operations that a CPU can perform. Some examples of these operations are addition, subtraction, or other arithmetic operations; other possibilities include operations that control what instruction will be executed next. All C++ programs must be converted into machine instructions by a compiler before they can be executed by the CPU.

An assembly language program is the human-readable representation of a set of machine instructions; each assembly language statement corresponds to one machine instruction. By contrast, a C++ program consists of much higher-level operations which cannot be directly translated one-for-one into machine instructions.