A portal gun is a fictional device commonly found in video games and science fiction. It allows users to create portals on flat surfaces, enabling instant travel between two locations. The concept is popularized by the video game series Portal, where players solve puzzles using this technology. In the Portal games, the portal gun creates two linked portals: one for entering and another for exiting. This mechanic allows players to navigate complex environments and overcome obstacles creatively. The idea of portal technology raises interesting questions about space, time, and the nature of travel in both fiction and theoretical physics.