An electromagnetic field is a magnetic field created by electricity.
This term can refer to the overall effect throughout the universe of magnetism reacting with electricity, but in a localized sense it can refer to an area of exceptional electromagnetism or a magnetic field created artificially using coils, through which an electric current is passed, to create magnetism. The direction of this field depends on the way the current is send through the coil. The strength and radius of the field is limited to a local area around the object. The higher the current is which passes through the coil, the stronger the field and it effects will be with respect to the distance of the object.
The USS Voyager used magnetic interlocks to constrain the anti-matter flow.