$ ls -l `which perl`
-rwxr-xr-x 2 ken None 169225 Jun 23 20:35 /.../perl

$ ls -l `type perl`
ls: cannot access 'perl': No such file or directory
ls: cannot access 'is': No such file or directory
-rwxr-xr-x 2 ken None 169225 Jun 23 20:35 /.../perl