A variety of related manual defect detection activities go by names such as inspection, formal inspection, Fagan inspection, walkthrough, peer review, formal technical review, and so on. In the most general sense, these are all ways in which someone other than the creator of a software work product examines the product with the specific intent of finding errors in it.
Software Inspections were introduced in the 1970s at IBM, which pioneered their early adoption and later evolution. Michael Fagan helped develop the formal software inspection process at IBM, hence the term “Fagan inspection.”
Reference: Fagan, M. “Design and Code Inspections to Reduce Errors in Program Development.” IBM Systems Journal 15, 3 (1976): 182-211.
See also *Software Inspection*.