Perhaps its most powerful command is the search box:

To search, simply type one or more words into the search box and click on the Search button. Results are instantly displayed. To clear the search, click on the that appears next to the Search box.

Note: the search box always searches for the exact full text you type; e.g., if you type 'red cars' it will only find documents with 'red cars', not also documents that have only the word 'red' and documents that have only the word 'cars'.

Searches scan across all of the current applications, but not across other application instances. This way you can keep your information partitioned by keeping it in different application instances.