In our system, we always show at least three host records for every domain name:

• The www record specifies where you want visitors to land if they type, for instance, www.example.com.
• The @ (“at”) record specifies where you want visitors to land if they type your domain name without a host name, such as example.com.
• The * (“star”) record specifies where you want visitors to land if they type any other host name, such as sales.example.com.

출처: http://namebargain.com/help-center/