The term TEST MODEL is used to describe a process of testing a product or service before it is released to the public. This process typically involves two stages: BETA and DEMO. BETA is short for 'BETA testing' which is a type of testing that takes place before a product is released to the public. It is usually done by a select group of people who are given access to the product in order to provide feedback on its performance. DEMO stands for 'DEMONSTRATION' and is a type of testing that takes place after a product has been released to the public. It is typically done by a larger group of people who are given access to the product in order to demonstrate its features and capabilities.