Homotopy is a concept in topology, a branch of mathematics that studies the properties of space that are preserved under continuous transformations. It involves the idea of deforming one shape into another without tearing or gluing. Two functions are said to be homotopic if one can be transformed into the other through a continuous series of steps. In more technical terms, homotopy provides a way to classify spaces based on their fundamental characteristics. For example, two paths in a space are homotopic if one can be continuously transformed into the other while staying within the space. This concept is essential in areas like algebraic topology and has applications in various fields, including physics and computer science.