A Seifert surface is a type of surface in mathematics, specifically in the field of topology. It is used to study knots and links in three-dimensional space. A Seifert surface is a connected, oriented surface that is bounded by a given knot or link, meaning it has edges that correspond to the knot or link itself. These surfaces are named after the mathematician Heinrich Seifert, who introduced them in the 1930s. Seifert surfaces can help determine properties of knots, such as whether they are equivalent or how many times they wind around each other. They play a crucial role in knot theory and topology.