SharePoint Stack Exchange is a question and answer site for SharePoint enthusiasts. It only takes a minute to sign up.
Sign up to join this community
I am using SharePoint Online which is running SharePoint 2013. When I visit the Site Settings page, it looks like this:
/_layouts/15/settings.aspx
Whereas on SharePoint 2010 it was:
/_layouts/settings.aspx
What is the reason for this? Is it something to do with 2013 on-premise running 2010 deployed solutions and having them in the 14 hive folder? Maybe I'm way off the mark but I'm wondering if it has 15 in the URL as it has to support 14 as well.
Till SharePoint 2013, migrations from Vn to Vn+1 were done by upgrading the DB and moving all artifacts (including thus from the "_layouts" folder, i.e. application page) to the new version. From SP2007 to SP2010, there was a "keep 2007 look&feel" mode, but it was just SP2010 applying old master pages/CSS.
From SP2013, the story is different, and there's a kind of "backward compatibility" mode: migrated SP2010 sites still use the actual 2010 "_layouts" folder. To avoid breaking URLs, the 14 _layouts is the "_layouts" one (no version in path). It's mapped to the LAYOUTS folder of the \14 hive.
The "/_layouts/15" folder contains 2013 version of the application pages. It's mapped to the \15 hive LAYOUTS folder. All new pure SP2013 sites are in 2013 mode, and use the /_layouts/15 path.
