A projective space is a type of geometric space that extends the concept of ordinary geometry by adding "points at infinity." In a projective space, lines that would normally be parallel in Euclidean geometry intersect at these points at infinity, allowing for a more unified treatment of geometric properties. The most common example is the projective plane, which can be thought of as the set of all lines through the origin in a three-dimensional space. Projective spaces are important in various fields, including algebraic geometry and computer graphics, as they help in understanding perspectives and transformations.