A cataloger stores details of all your photos, allowing very fast searches, allows you to keep lots of different virtual collections, keep track of different versions of the same thing.
A browser, sorter, tagger is like a file explorer taking in details of all the files, allowing you to browse them and add tags, ratings etc. It allows you to sort them rapidly, so that you can decide what to keep or not etc. PM allows you to add tags to the photo itself as well as to a sidecar (not many progs did that at the beginning though a number do now). Most cataloging products allow you to do all of these as well as being catalogers, but they won't (usually at least) be so fast.
You need to realise that this market is full of very, very specialised programs mostly at high prices. Adobe Bridge is another example of the same sort of product. Some progs specialise purely in downloading images from cards and cameras (eg Breeze Downloader).
Let me tell you what I am looking for in a photo organizer/cataloger. I appreciate your suggestions.
I currently have about 250K images, disorganized into some 4K folders that people lumped them into, taking over 100GB with more coming once in a while. By and large they are JPEGs with a handful of GIFs and PNGs, no RAWs.
I need to assign multiple tags to them so that I can say, for example, "give me the images tagged as sports, kids, outdoors" or be more specific and request "soccer", "baseball" or "tennis" instead of "sports.
I want the tags to be hierarchical, so that tagging an image as "dolphin" will implicitly return it when searching for "mammals" or "animals". Ideally, it would be possible for tags to participate in multiple hierarchies so that the "dolphin" tag above will also match "marine", etc. I expect to have lots of tags and categories, including cross-category tags. This should probably be a feature of the search, see below.
I also need the program to be flexible: allow adding/removing/changing tags on single images, folders, folder trees or just groups of selected images; changing the tag/category structure and having the changes automatically applied; moving images between folders; etc.
And last but not least, I want it to be FAST, both when indexing and when searching.
Does such application exist?