Sometimes, you want to see all of your installed applications in Unity, without having to "search". Doing so will probably make you discover a small world of great software installed in your computer.
First of all, click on the Unity menu:
You should then click on the "More apps" icon. You will get a screen that looks like this:
At this point, you have three list:
You also have a really important feature: "Filter results". Once you have activated it, you can see how applications are categorised in your system:
For example, click on "Internet": you will see all of the internet-related applications you normally use, you have installed, and might want to install:
One little feature that is often missed is the "See X more results": this will expand the list of applications in that section, so that you have a more complete view of what you can see.