How is PowerShell's RemoteSigned execution policy different from AllSigned?

Obviously AllSigned requires all modules/snapins and scripts to be code-signed. RemoteSigned only requires signing for remote files. What are remote files?

The canonical answer is on the PowerShell blog: http://blogs.msdn.com/b/powershell/archive/2007/03/07/how-does-the-remotesigned-execution-policy-work.aspx

But the bottom line is: RemoteSigned only requires code-signing on modules/snapins and scripts which are flagged as from the "Internet" zone in the 'Zone.Identifier' alternate data stream, unless you have "Internet Explorer Enhanced Security" activated, in which case it also includes "Intranet" flagged files and UNC paths.

The difference being that RemoteSigned will run scripts locally that aren't signed, whereas AllSigned requires all scripts to be signed regardless of their origin.