e938ed2d_SharePoint_Server__2007__2010___SharePoint_Farm_Solution
[0] Scope [Sandboxed Solution] Sandbox solution scope is limited to Site Collections in which they are activated. [Apps for SharePoint] app are installed within the same scope of the SharePoint site or at the Tenancy Scope. The tenancy scope is just to make sure that all the tenant site can install the app at the site level. [SharePoint Farm Solution] 
Farm solutions can be installed for any scope such as at Farm, Web App, Site Collection, Site level.
A Point For Sharing On SharePoint Server (2007, 2010)
SharePoint Farm Solution