Press your chosen hot-key (default Enter key) to display the FARR window, then just start typing the first letters of the application you want to launch and the results appear instantly. Hit enter to launch the top result, or refine your search with special modifiers and commands.
There are several configuration options (bit difficult) to make FARR better. It lets you quickly run web searches, send email, manipulate files, control on-screen windows, and much more. Build and share custom commands or install plug-in to add tons of new features, like live search features for your clipboard history and your internet bookmarks; a popup a calculator with history tape and persistent variables; and many more.