On FK spaces

The present thesis consists of four chapters. In the first chapter, brief history of K- and FK- spaces and general knowledge were given. In the second chapter, for understand other chapters some basic definitions and the theorems and basic concepts such as locally convex space and sequence space were mentioned.In the third chapter, K- and FK- space were defined and some properties of these spaces were examined.In the fourth chapter, some subspaces of K- and FK- spaces were examined by section operators. Using the properties of these subspaces, relations among the dual spaces were given. Then, some subspaces generated by Cesaro means were investigated.