An auditor is a person whose job is to carefully examine financial records, accounts, or processes to make sure everything is accurate and follows the rules. Think of an auditor as a professional checker who looks through a company's books to verify that the numbers add up correctly and that no one has made mistakes or tried to hide anything dishonest.

When a business hires an auditor, that person reviews receipts, bank statements, and financial reports to confirm the company is telling the truth about how much money it makes and spends. Auditors help catch errors before they become bigger problems. They also help prevent fraud by making sure everyone knows their work will be reviewed.

Schools and governments also use auditors. A school district might hire an auditor to review how it spends taxpayer money. Auditors don't just look for problems: they also confirm when organizations are doing things right, which helps maintain trust.

To audit something means to examine it this way, so you might also audit a class (sit in to learn without getting a grade) or audit a process to see if it works efficiently.