Once you get past the Line password, you are logged in IOS software environment of the router. IOS is separated into two levels of privileges, EXEC and Privileged EXEC .
EXEC level contains only basic, non-destructive commands. While in enable mode provides access to more commands. EXEC level commands primarily allow you to view the router. Switch mode commands are more powerful because they permit you to configure the settings of the router. These commands are potentially vicious commands erase command is a good example.

Two types of passwords can be used to restrict access to Privileged EXEC (enable mode): Insert the password and enable secret password. The idea of a "secret password", it seems silly at first glance. Of course all passwords are secret, or at least, they should be. The fact that Cisco engineers having in mind here is the level of encryption used to mask the password from illegal users.