Displacement current is a term commonly used in electromagnetism to describe the flow of electric charge without the presence of any physical movement of charges. Synonyms for the term include displacement flux, displacement flow, and displacement charge. The concept of displacement current was introduced by James Clerk Maxwell in 1861, who postulated that electric current could exist in a vacuum by means of a changing electric field. This led to the development of Maxwell's equations, which provide a mathematical framework for understanding the behavior of electromagnetic waves. Alternate terms for displacement current may be used in different contexts, but they all refer to the same physical phenomenon.