Abstract algebra is the study of algebraic structures, which are sets with operations defined on them. It focuses on studying the properties and relationships of these structures, such as groups, rings, and fields. This branch of mathematics explores concepts like symmetry, transformations, and equations, providing a foundation for other areas of mathematics and applications in various fields such as computer science and cryptography. By studying abstract algebra, mathematicians can gain a deeper understanding of the fundamental structures and principles underlying mathematical systems.