patterns(Principles that guide developers as they assign responsibilities to software classes and design system behavior. They are most useful when creating collaboration diagrams where messages imply responsibility)
model 1. A representation, usually on a smaller scale, of a device, structure, etc. 2. A quantitative or mathematical representation or computer simulation which attempts to describe the characteristics or relationships of physical events
model(A mathematical or graphical representation of a real-world situation or object. For example, a mathematical model of the distribution of matter in the universe, a spreadsheet (numeric) model of business operations, or a graphical model of a molecule)