It is virtual creation of a real environment or situation. It make you feel that you are experiencing the real situation by stimulating their vision and hearing.
Augmented Reality or AR
This puts computer-based enhancements over an existing reality to add more meaning to the ability to interact with it. AR is created in apps and used on mobile devices to mix digital components into the real world.
How are they similar?
Technologically, both leverage some of the similar technology types, and they both offer an enhanced or better experience.
In the world of Entertainment, both the technologies provide experiences which are becoming very common. Leading tech experts are researching and developing new adaptations, making improvements, and releasing advanced products and apps which support these technologies for tech-savvy users.
In the world of Science and Medicine, both have great power to change the face of the medical field by introducing things like remote surgeries.