What Does Serial Processor Mean?

A serial processor is a processor type used by systems where the central processing unit (CPU) carries out just one machine-level operation at a time. The term is often used in contrast to a parallel processor, which features more than one CPU to perform parallel processing.

Techopedia Explains Serial Processor

Various single-core processors can be used together for handling serial processing by means of parallel computer clusters that are networked, or by operating multiple processors on a single motherboard.