Vision is a combination of human and alien technologies. Ultron had the body made using an advanced Earth technology for synthesizing human tissue, but it also had vibranium incorporated into the structure by exposing the developer to alien technology. Ultron intended to upload his core intelligence into the new body, but the Avengers intervened before the upload was complete, capturing the body. Tony Stark then sought to install a more friendly AI into the body. Despite some disputes with the other Avengers, the upload of a more friendly intelligence was eventually completed. The android assisted in the defeat of Ultron and subsequently became an Avenger itself.
The Vision has superhuman strength and durability. The incorporation of vibranium into its structure suggests that it can absorb unspecified amounts of energy in a variety of forms without suffering damage, and it endured numerous attacks from Ultron's robot bodies without suffering any harm. As the Vision is an artificial life form instead of a non-living robot, it is likely capable of healing damage that it does sustain.
An Infinity Stone (the "Mind Stone") was attached to the body by Ultron to give it the capacity to hold its artificial intelligence. In addition to whatever mental capabilities the stone grants, it is also able to generate powerful energy blasts.
Vision is able to alter his own density. By lowering his density, he can move through solid objects. It is not yet clear whether he can increase his density beyond normal or what effect that would have.
Vision is also capable of independent flight, but its top flight speed is not yet known.
In Marvel comics, the Vision is an android with the power to alter its own density, and the jewel in its forehead is able to generate blasts of solar energy. It is not normally associated with an "Infinity Gem".