Force.com Perspective

A perspective is a concept used by Eclipse to describe a collection of user interface components.
For example, Eclipse has built-in perspectives called Java and Java Debug. By
installing the Force.com IDE, you’ve added a perspective called Force.com. 
If you do not see the Force.com perspective, click the menu option Window-->Open
Perspective ? Other, select Force.com from the Open Perspective dialog, and click the
OK button
The Force.com perspective includes several user interface panels, called views. Execute Anonymous and Apex Test Runner.
It also adds a new type of project called the Force.com Project, which is shown in the leftside
Navigator tab.The first step to using the Force.com IDE is to create a Force.com
Project.