Isolated Metadata Model
The metadata model is a set of interfaces that represent metadata. There is great similarity between metadata from different sources, so by programming against this model and providing an adapter to your metadata source templates can work with multiple metadata sources.
Names in the models end iwth the suffix "Data." This distinguishes them from the template information which are suffixed with the word "Info." This is important because there are often identically named concepts that appear in two very different forms. For example: ObjectData represents data about the entity level for creating .NET code. What object are you creating code for and its metadata. The Template infrastructure has the quite distinct concept of ObjectInfo which contains data about the actual source code you're curently creating.
The model is the friendliest possible from the perspective of the template. It maps to the concepts a set of templates needs to work with.