In which prototyping model the final product is decimated into a series of small prototypes and each prototype is developed separately.

Software architecture is the set of structures needed to reason about a software system and the discipline of creating such structures and systems. In other words, Software Arcitecture describes how software components — subroutines, classes, functions, etc. — are arranged, and the interactions between them.
Some types of software architecture patterns are: Layered (N-tier) architecture. Client-server architecture. Event-driven architecture.