Scan profiles are used to determine what information a particular scanner will collect. For instance, PDQ Inventory has scan profiles that collect installed applications, hot fixes, registry values, and more (see below).
Sometimes you need a quick scan, without waiting for all details to be collected. For instance, if you just deployed an application and you want PDQ Inventory to reflect the new install, create a scan profile that just scans for Applications and Computer Details. If you have hundreds (or thousands) of computers, you can reduce your scan time considerably.
Users & Groups
Shane walks you through this feature in the video below.