Machine code is machine language that is understandable by Central Processing Unit (CPU) of computer. All programs which is written in any language at the end must be converted into this (Machine Code) language to perform execution because CPU can understand only Machine code.Machine codes are difficult to read for human , that’s why we use highvlevel programming language like c,c++, Java .. which is easily understandable. We do use of compiler to convert High level Programming language into machine code.
Every processor family has its own machine code instructions.