Two audits, two questions.
ISO certification is not one audit. It is two, and each answers a different question.
Stage 1: is the system ready?
The auditor reviews your documented management system, confirms the scope and sites, and checks you are ready for Stage 2. Gaps found here can be fixed before Stage 2, which is why Stage 1 saves time and money.
Stage 2: does it work in practice?
The auditor tests how the system actually runs, through records, evidence and interviews with the people doing the work.
Then the decision.
A certification decision is made by someone who did not take part in your audit. That separation is what gives the certificate its weight.
After that, a surveillance audit in each of the next two years keeps the certificate current, and recertification renews it in year three.
