I was reading about the Determine permission levels and groups in SharePoint 2013 and there I saw two words :- Visitors & Viewers. SO what's the difference between them?
By looking to the term it seems like both the permissions are same but when we talk in terms of programming then there is allot difference between these two permission level.
Visitors: This user has the permission to only read(not modify) the content of SharePoint, it means if you are trying to fetch the contents from SharePoint in your program using any object model then it will allow you to read the contents.
Viewer: This user has the permission to only view(Not modify/Download) the content of SharePoint, it means if you are trying to fetch the contents from SharePoint in your program using any object model then it will give you access denied error and you cannot read the SharePoint contents in your program.
This is just basic difference I am telling just to clear your confusion.
Let me know if you want to go more in depth.
The difference between Visitors and Viewers are :
Visitors : Visitors are able to open file and library .They can view document in Read-Only mode but they cannot edit any document.They have Read permission ,They can also read content of site as well as download it.
Viewers : Viewers can open file and library in read-only mode but they cannot be able to download anything as well as they can access file only in browser rather than any application.They can just see content but cannot download it.
There are out-of-the-box "Permission levels", and among them:
- Read - Can view pages and list items and download documents
- View Only - Can view pages, list items, and documents (not download)
And there are out-of-the-box Groups, and among them:
- ... Viewers
- ... Visitors
For a particular resource, you can provide an access for a "Group" with "Permission" level.
By default, "... Visitors" group has "Read" permission and "... Viewers" group has "View only" permission.