Here is a brief summary of each product based on user feedback. TrustRadius has collected dozens of user reviews of all three versions, so you can easily discover the common use cases and pros & cons of each product.
QuickBook’s own website heavily emphasizes the online version of the product. This is a trend that has been discussed far beyond Intuit products. So what will the future look like? To many in the Quickbooks community, the inevitability that the desktop products will eventually be discontinued in favor of online products is obvious. As of writing, Online now offers nearly all the features of the desktop software and several additional ones. Much of the recent development effort has been on bringing the online version up to feature parity with the desktop products. However, Quickbooks Online has been Intuit’s clear focus for a number of years, along with mobile. Quickbooks for Mac, as the name suggests, is a desktop tool for Mac users, Quickbooks Pro is a desktop accounting tool for small businesses, and Quickbooks Online is a subscription-based cloud accounting tool. The company offers multiple versions of its product to serve different user populations. The Quickbooks family of accounting products from Intuit has maintained a vastly high portion of the small business market share for over a decade.