Software is the set of instructions and programs that tell the computer what to do.
People often point to the whole machine and say software, or mix software with the operating system. That makes later lessons harder.
Software is the logical part of the computer. It is made of instructions, not physical parts.
Software is the invisible set of instructions that helps the computer do jobs.
Software is the logic layer that runs on the machine. It is not the metal, plastic, or wires.
People often use software to mean everything on the screen. But software is a broad category, and the operating system is only one important part of it.
Study the larger concept after the word itself becomes clear.