Virtualization

Virtualization, or sometimes Digitalization, is a process in which a thing, living or otherwise, is transported from the Scanners into Lyoko. This process was created by Franz Hopper as a way to assure the escape with his daughter to Lyoko from the goverment agents. Team Lyoko uses this process to stop XANA's attacks. The virtualization process is usually controlled by Jeremie, sometimes by Aelita, and rarely by Yumi, Ulrich or Odd.

Virtualization scans a person's physical features and their DNA. These things are combined with the person's powers and attributes, their brain patterns are also analyzed and the central nervous system is scanned to ascertain the molecular structure. Their matter is then converted into energy which is stored in the computer for materialization. If the supercomputer shuts down whilst the user is inside, the user will be locked up until someone turns it back on. XANA can prevent users from leaving Lyoko by stealing their memories, mess up the program that gets them back to Earth or by imprisoning them inside a simulation bubble, such as the one used in the episode Ghost Channel. 

How Virtualization Works 

The scanner process takes place in three steps. The first step seems to pressurize the scanner. This appears as a slight upward wind within the scanner. The second step levitates the person while a circular scanning ring records their physical makeup, (in the first season, the second step spins the person slowly white the scanner ring records the physical makeup). The final effect creates some sort of energy pulse within the scanner. This appears as a much greater gust of wind within the scanner which blows the person's hair up followed by an all-encompassing flash of light. This is the step that takes the person apart and "teleports" them into the virtual realm. The scanner doors open after this to allow others to use the scanner and repeat the process. 

 sumber : www.lyoko.wikia.com