In the basic case, a model is Python class that maps to a single database table. The attributes of the class map to columns in the table and an instance of the class represents a row in database table. The models inherit from
django.db.models.Model which provides a rich API for adding and filtering results from the database.
Model binding is the process of taking HTTP parameters, typically in the Query String of a GET request, or within POST body, and applying it into an object that can then be validated and consumed in an object-oriented manner without the need for Controller actions having intimate knowledge of how to retrieve HTTP parameters.
In other words, model binding is what allows actions, in MVC, to have either parameter(s), whether it being a value type or an object.
Aggregations are methods allowing the execution of operations on (individual and/or groups of) rows of objects derived from a Model.