QuickBooks Online and QuickBooks Desktop are two different versions of Intuit's accounting software designed for small and medium-sized businesses. The main difference between them lies in their operating mode, with QuickBooks Online being cloud-based and accessible from any device with an internet connection, while QuickBooks Desktop is installed locally on a computer or network. QuickBooks Online offers real-time collaboration, better accessibility to accounting data, and integration with other apps through its Apps tab and Zapier. On the other hand, QuickBooks Desktop provides more control over data, stability, and security, making it suitable for businesses that prefer local installation and don't require extensive collaboration. Ultimately, the choice between QuickBooks Online and QuickBooks Desktop depends on a business's specific needs and preferences, including budget constraints, remote collaboration requirements, and feature priorities.