We had an idea in #949 to have "context" objects that enabled the easy and convenient creation of training algorithms. We eventually came to like this idea so much that it expanded considerably, until we came to think it actually a good idea that most components (whether trainers or not) could work through this object, to the point where eventually in in #1098, there was a "master" context, of which the formerly independent contexts became properties of that master context.

The newer things that were added were then called "catalogs," for example:

However the old objects retained the type names they had back when they were independent.

We ought to probably standardize the name of these things as being "catalogs." E.g., things in here with the type name suffix Context should change that to Catalog, things that are catalogs but aren't named that yet (DataOperations) should be standardized as well.