Yes, SharePoint data can be stored locally on your PC, for easy access even when you’re offline. Next time you are online, changed documents will be synchronised with the server.
No, you can purchase SharePoint Online as a standalone solution but because of its integration with Exchange Online and Lync Online, Microsoft sells SharePoint within a package at a more economical price.
SharePoint is a feature rich and easy to use content management system that includes a long list of capabilities but at its core, here are a few of the key points that make SharePoint better than just using a file server to store and manage your documents:
Yes, SharePoint makes it very easy to setup sites (sub-sites) that are secure but accessible to external users outside of your organisation.
Yes, you can. You can access SharePoint with all the latest browsers but also SharePoint has mobile applications that you can download for your tablet.