The term artifact (or artefact) is widely used within computer (or digital) forensics, though there is no official definition of this term.
The definition closest to the meaning of the word within computer forensics is that of the word artifact within archaeology. The term should not be confused with the word artifact used within software development.
If archaeology defines an artifact as:
something made or given shape by man, such as a tool or a work of art, esp an object of archaeological interest
The definition of artifact within computer forensics could be:
An object of digital archaeological interest.
Where digital archaeology roughly refers to computer forensics without the forensic (legal) context.