A coilgun is a type of electromagnetic projectile launcher that uses coils of wire to accelerate a metal projectile. When an electric current passes through the coils, it creates a magnetic field that pulls the projectile forward. As the projectile moves, the current is switched off in the previous coil and turned on in the next, allowing for continuous acceleration. Coilguns are often compared to railguns, which use two parallel rails to achieve similar effects. While coilguns can be simpler to build and operate, they typically have lower velocities than railguns. Both technologies are of interest in military and scientific applications.