- Web template requires only the proper rights to upload the .WSP, Web Template is a sandboxed solution
A site definition requires physical access to the file system of the servers in the farm.
- A web template can be deployed and used in the cloud
A site definition cannot be deployed in a cloud environment (SharePoint Online or Office 365),
- A web template can be versioned without affecting existing site instances
- Changes in the pages defined in a web template, will be available only in new sites,
Changing the layout of pages provisioned through a site definition will also affect previously deployed sites
- A web template can do almost everything you can do with a site definition.