What Does Garbage Mean?

Garbage, in the context of computers, is used to refer to any unwanted or unused data occupying memory space. Unallocated memory must be free of garbage values before allocating them, as the presence of garbage values may cause security issues and exceptional conditions.

Techopedia Explains Garbage

Under normal usage, the word garbage refers to any waste product or something that is no more useful. Just as garbage does not occur naturally in the real world, garbage in the computing world is also created by programmers and their style of writing programs.