This book the third book in the four-volume series in algebra deals with important topics in
homological algebra including abstract theory of derived functors sheaf co-homology and an
introduction to etale and l-adic co-homology. It contains four chapters which discuss homology
theory in an abelian category together with some important and fundamental applications in
geometry topology algebraic geometry (including basics in abstract algebraic geometry) and
group theory. The book will be of value to graduate and higher undergraduate students
specializing in any branch of mathematics. The author has tried to make the book self-contained
by introducing relevant concepts and results required. Prerequisite knowledge of the basics of
algebra linear algebra topology and calculus of several variables will be useful.
