Inspection is a formal review process that verifies a product's compliance with requirements. It involves careful planning, meetings to examine the product against designs and documentation, and rework based on feedback. In contrast, walkthroughs are more informal meetings where the author presents an artifact and peers provide spontaneous comments and questions to identify defects, with minimal documentation and tracking of issues. Both help identify defects, but inspections are more rigorous and result in corrections, while walkthroughs primarily inform participants.