Lightroom catalog ircat

Just to clarify, when you import image files to Lightroom info about those files, including all the things that you do with those files is stored in a data based file called by default Lightroom Catalog with an extension .lrcat (.LRCAT) to symbolize Lightroom Catalog. This file is to be kept safe if it is deleted, damaged, corrupted you will lose all the info done with the image files. Backups need to done regularly and stored in a different hhd.

With each upgrades .e.g. 7 to 8 or 9 Lightroom will copy the existing Catalog file and create a new one for the upgrade version. You will normal see -2 added to the Catalog name.

Do a screen capture to show folder where the Catalog file is located to show the contents.

The catalog is literally the only file Lightroom opens. When you import images, what you are doing is adding records to the catalog which is a database. The images don't go into the catalog, but information about where the images are located and all the adjustments you make using Lightroom and other information associated with those images is what is stored in the catalog. Technically, you only need one catalog. Some users create catalogs for every project or client. Other users will create a catalog for each year. Other users will come up with some convoluted method of scattering images among countless catalogs thinking this is more logical and makes it easier to locate images in the future. In reality, keeping images centralized in a single catalog and organizing them with keywords and collections greatly simplifies the organizational process. I don't know what the contents of your various catalogs might be. Only you can determine if they are duplicates or backups or, well, you get the idea. If you can tell by the dates on them whether or not they have been used recently then you can decide whether or not you want to delete them. Each time a catalog is opened and used its date will be modified. I suppose this has been a rather evasive answer, but having been given this information perhaps you can look at the catalogs you have and decide whether or not you want to keep all the catalogs or whether there are some of those catalogs you feel you can safely delete. Just remember that by deleting catalogs you are NOT deleting any of your images.