QuickBooks is accounting software that helps small businesses track finances like revenue, expenses, and profits. It generates automatic reports on key metrics and allows sharing financial information with accountants or employees. QuickBooks also helps create invoices and track inventory. The H202 error occurs when there are issues entering or saving data in QuickBooks. This could be due to incorrect, duplicate, missing, or invalid entries. The error suggests checking for data errors. Potential causes include computer or internet issues, while solutions include testing internet speed, using file doctor, adjusting firewall settings, ensuring QuickBooks services are running, and modifying the hosts file.