Electromagnetism is the study of the electromagnetic forces between electrically charged particles that is carried by electromagnetic fields composed of electric fields and magnetic fields, and it is responsible for electromagnetic radiation such as light. The field uses the tools of vector calculus for solving static and dynamic properties of electromagnetic fields and addresses special cases of static charge distributions (electrostatics), time-independent current distributions (magnetostatics), and electric and magnetic properties of matter (dielectrics and magnetic media).
Thumbnail: Animation showing the electric field of an electric dipole. The dipole consists of two point electric charges of opposite polarity located close together. A transformation from a point-shaped dipole to a finite-size electric dipole is shown. (CC BY-SA 3.0; Geek3 via Wikipedia)