The holographic principle is a theory in physics suggesting that all the information contained in a volume of space can be represented as a two-dimensional surface. This means that the three-dimensional world we perceive may be a projection of information stored on a distant surface, similar to how a hologram works. This idea emerged from studies in string theory and black hole thermodynamics, particularly the work of physicist Leonard Susskind and others. It challenges our understanding of space and time, proposing that the universe's fundamental nature might be more about information than physical matter.