What do you understand by the term prototype? What is the relevance of prototyping to systems development?

Relevance of prototyping to systems development
A prototype is an early, rapidly constructed working version of the system. The working model helps users understand the system that is being developed.
Prototyping produces a less-expensive model
 Can eliminate problems before the final version
 Goal is to develop a working model quickly
 Early way to test essential system features
 Prototype can be upgraded or replaced during later SDLC phases