Microsoft Dynamics CRM Online is a cloud offering of Microsoft Dynamics CRM provided by Microsoft. Similar to other online office subscriptions, Microsoft Dynamics CRM online is managed under office 365 platform. Microsoft Dynamics CRM is also offered as on premise or partner hosted. Partner hosted is nothing but Dynamics CRM is deployed into one of the partner’s servers and you will be given access.

Microsoft Dynamics CRM online can be subscribed from Microsoft online services via

• Office 365 admin portal
• Convert a trail version to paid version
• Via Volume licensing

Though, Microsoft Dynamics CRM is subscribed through office 365 admin portal, you don’t need to buy any office products.

Microsoft Dynamics CRM can be access via web browser, which means you don’t need to install any software’s. However, there is a limitation on the browser version where you can access Dynamics CRM online without any issues

Microsoft Dynamics CRM can also be accessed on few other client applications like Outlook, phones, tablets however users need to install certain app’s like Microsoft Dynamics CRM for outlook, Microsoft Dynamics CRM for Phones, Microsoft Dynamics CRM for tablets.

Windows Operating system requires for Outlook remains same as mentioned in the table for Google Chrome browser however, Microsoft Office 2010, 2013 or 2016 are supported.

Microsoft Dynamics CRM subscription can be purchased for a minimum of 5 user licenses. This also comes with 5 GB of storage. If you buy 25 or more licenses, Microsoft provides you with 1 non production instance.

There is more information available on the software and hardware requirements and mobile phone requirements at TechNet