GigE Vision is a framework for transmitting images over an Ethernet connection. It consists of protocols that define how to configure a camera and to transfer the image data. Every computer with a fast Ethernet card is compatible with the GigE Vision framework. So GigE Vision requires only an ethernet card, whereas CoaXPress and Camera Link require a framegrabber.
The maximum transfer speed of a GigE Vision camera (assuming a gigabit Ethernet card in the computer) is 1000 Mb/s.