Instruction Set - Object Code (Machine Code)
An object code or object module is a plain binary file composed of a series of Cpu instructions (language machine) that a programmable device (generally a CPU) can understand.
The term code indicate that it's generally the product of a code compiler targeting the CPU ISA architecture.
In order to be executable by an OS, the object code must be wrapped in a object file with metadata.
Linux: See objdump