Inspection is the most common method of attaining standardization, uniformity, and quality of workmanship on the product, it is also checking and controlling the product quality after comparison with the established standards and specifications.
It is the function of quality control and check whether it can be accepted by AQL (Acceptance Quality Level), set by customer.
An inspection helps to control quality, reduces manufacturing costs, eliminates scrap losses, and assignable causes of defective work by using an indispensable tool of the modern manufacturing process. “Inspection activities can overlap with testing and certification activities where these activities have common characteristics.  However, an important difference is that many types of inspection involve professional judgment to determine acceptability against general requirements, for which reason the inspection body needs the necessary competence to perform the task” (Source from ISO17020:2012).