what are the types of audit?

There are three types of audit
First party Audits
Second Party Audits
Third Party Audits

First Party Audits
These audits are performed by the company (or a department within the company) upon itself
Second Party Audits
Its an audit of another organization’s quality program not under the direct control or within the organizational structure of the auditing organization
usually performed by the customer upon its suppliers (or potential suppliers) to ascertain whether or not the supplier can meet existing or proposed contractual requirements
Third Party Audits
It is an assessment of an organization’s quality system conducted by an independent, outside auditor or team of auditors