The stage at which the project is during development. Means that the product is ready, but is still in the process of public testing, bug fixing and optimization improvement. This term is often used in website development.
Backend is the hardware and software part of the server that is responsible for the logic and mechanics of web services or applications. It is responsible for the interaction of the server and data (content). Quite often this term is used in website development.
The person who tests and verifies the product to identify bugs. Subsequently, he or she submits information about these errors to the developer for correction