If you want to read the original article on inspections, see "Design and Code Inspections to Reduce Errors in Program Development" (Fagan 1976).
An inspection is a specific kind of review that has been shown to be extremely effective in detecting defects and to be relatively economical compared to testing. Inspections were developed by Michael Fagan and used at IBM for several years before Fagan published the paper that made them public. Although any review involves reading designs or code, an inspection differs from a run-of-the-mill review in several key ways:
Checklists focus the reviewers' attention on areas that have been problems in the past.
The inspection focuses on defect detection, not correction.