trailing slash in location

[amodpandey]

Please help me understand

The below works

     location /stats/ {
        proxy_pass http://example.com;
     }

or 
     
     location /stats {
        proxy_pass http://example.com;
     }

or

     location /stats {
        proxy_pass http://example.com/stats;
     }

or

     location /stats {
        proxy_pass http://example.com/stats/;
     }

or

     location /stats/ {
        proxy_pass http://example.com/stats/;
     }

But this does not work

     location /stats/ {
        proxy_pass http://example.com/stats;
     }

Smlly when stats is an upstream

This works

   location /stats {
     proxy_pass http://stats;
   }

but this does not

   location /stats {
     proxy_pass http://stats/;
   }

What difference it makes when we have uri in the proxy_pass?

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,232966,232966#msg-232966