Unified Modeling Language $($UML$)$ specifies, visualizes, constructs, and documents different artifacts of software development projects. Which of the following describes UML?

It is a language that can be an extension to programming languages, such as C$++$ and Java.

It is a technical language used only by technical people.

It defines key diagrams that can be used not only by developers but also by business users, common people, and anybody who may be interested to understand a software system.

It is a special purpose language that captures the development sequence for software systems.