An electron beam is a stream of electrons that are emitted from a source and directed towards a target. This beam is created using devices like electron guns, which accelerate electrons through electric fields. Electron beams are commonly used in various applications, including scanning electron microscopy and electron beam welding. When the electrons in the beam collide with a material, they can produce various effects, such as generating X-rays or causing the material to heat up. The precise control of electron beams allows for detailed imaging and high-precision manufacturing processes in industries like electronics and materials science.