Welding, also known as welding, is a manufacturing process and technology in which metals or other thermoplastic materials such as plastics are joined by heating, high temperature or high pressure.

There are many sources of energy for modern welding, including gas flares, electric arcs, lasers, electron beams, friction, and ultrasound. In addition to being used in factories, welding can also be performed in a variety of environments, such as the field, underwater and space. Welding can be dangerous to the operator anywhere, so appropriate protective measures must be taken when welding. Possible injuries caused by welding include burns, electric shock, visual impairment, inhalation of toxic gases, and excessive exposure to ultraviolet rays.