Summary
In this section, we discussed WiX properties and the AppSearch feature. Properties allow you to store information during the course of the installation. Properties are referenced with square brackets when used in the attribute of another element. Be sure to look up whether or not a particular element attribute can interpret the square bracket notation. When used in the inner text of another element, the square brackets aren't needed.
We talked about some of the built-in Windows Installer properties. There are actually quite a few of these and we'll probably cover many more as we continue on. You've seen some that affect things like the Add/Remove Programs list, but there are also less flashy ones that Windows Installer uses just to do its job. However, knowing about them can be to your advantage when it comes to debugging or even creating conditional statements based upon them.
Windows Installer can do a variety of searches with its AppSearch feature: file, directory, registry, component...