Stable homotopy is a concept in algebraic topology that studies the properties of topological spaces that remain unchanged when we add higher-dimensional spheres. It focuses on the behavior of spaces as they are "stabilized" by considering their mappings into infinite-dimensional spaces, allowing mathematicians to analyze their homotopy groups in a more manageable way. This area of study is closely related to the work of homotopy theory and stable homotopy groups, which provide tools for understanding the relationships between different topological spaces. Stable homotopy theory has applications in various fields, including differential geometry and theoretical physics.