QuickBooks Online is Intuit’s web based accounting software application. You subscribe to it and make payments to Intuit. Login in and use the application from the internet browser like Chrome, Firefox and IE. Chrome browser works better for this application. They offer three product plans and the price vary starting from $13 to $40 per month. Currently, available features are not as robust as the desktop version. For example, if you need Inventory module, it is not that great. But, good part of this part of this application is you can login in from anywhere you have internet access and also can provide access multiple users. Also, they maintain backup of your data. There is no way to make a copy of company file data. Subscription plan is for one company one. If you need to another company, you will need to buy another subscription.
QuickBooks in the cloud usually refers to a company that hosts the QuickBooks desktop accounting software (like QuickBooks Pro, Premier) on their servers. You paid to that hosting company, not Intuit. You login in with internet and access the application on to your computer. QuickBooks desktop version is fully functional for your use. You can make a local back up of company file any time. Your hosting company will also provide auto backups of your data. You can also add as many company files as you want in desktop version. Prices may vary based on plans, but they normally range from $40 per month and up.