Vegans are a mysterious alien race. Almost nothing is known about the Vegans in Contact beyond the fact that they come from a planet orbiting Vega and are a peaceful and intelligent species.
As the Vegans grew more advanced they began to wonder if they were alone in the universe or if other life forms existed. As they developed the technology to explore outer space they discovered a mysterious series of wormholes built by an unknown species, and decided to use these as a means of interacting with other races should contact be made.
The Vegans eventually received a message from a planet called Earth, specifically a piece of footage of a Human named Adolf Hitler conducting and important ceremony. Not realizing the significance of the man depicted in the footage, they responded by returning the image, a sign that it had been received. This was encoded in a series of prime numbers, as it was believed that mathematics are the only truly universal language. Also hidden in the footage was a series of instructions which would allow a single person to travel through the wormholes to meet the Vegans.
The returned message was discovered by a scientist named Dr. Eleanor Arroway. This resulted in a huge controversy between both the scientific and religious groups, to the point where the first attempt to follow the instructions had been sabotaged by a religious suicide bomber. However, the machine was eventually built and Arroway was chosen to make the journey to Vega.
Upon arriving, Arroway found herself in a simulation created from her memories. She was approached by a Vegan who took the form of her father, who explained that this was only a "first step" and that with time humanity would continue to evolve before sending her back.