Glad to help.... Its called a catalog because you are basically building a database with info and thumbnails - some call them catalogs, others call them albums, etc.

Just remember.. you want to be sure anything you add to the catalog is also filed back into the metadata in your images... a step that many users do not do and learn to regret later. Ratings, keywords, IPTC info, etc should all be written back to your JPGS or Sidecard files - this will ensure you can easily recreate the catalog from your backup should your PC crash and (more importantly), that you can create a new catalog with NEW software should you want to move to the latest and greatest down the road... Good Luck!