A full deployment comprises two steps:
All assets are deleted from the target site.
All changed assets from the deployed project, and all appropriate existing assets, are deployed to the site.
Full deployments can be time consuming and resource intensive if the site has a large number of assets. However, it is especially useful (and sometimes necessary) to refresh assets when they are modified directly or are corrupt. It is also practical for small sites with few assets, as it can be performed relatively quickly.
Note: You can configure a full deployment to delete only certain file assets from a VFS with the SelectiveDeleteVFSService. This VFS lets you indicate explicitly which files to delete from the local file system during deployment.
