Some classes of linear and nonlinear operators

The work presented here is a survey of some known results in functional analysis, particularly in the field of Operator theory.
The study begins with definitions of linear spaces and some topological results which form the necessary background.
Chapter two is the heart of the work and deals with operators defined on a Hilbert space with mention of operators which are generalization of linear operators on finite dimensional spaces.
Chapter three looks at two classes of nonlinear operators known as Lipschitz and a-Lipschitz which frequently occur in applications. The last chapter is a brief look at the spectral theory of operators with no emphasis on a particular type of operator.