nevanlinna theory and some related problems

This is an expository manuscript to introduce basics of nevanlinna theory and some of its applications in complex function for the general audience with minimum back ground of complex analysis. we will see how the fundamental theorem of algebra for polynomials and the notion of their degree can be generalized naturally to entire and meromorphic functions. the aim of writing this note is to introduce this beautiful branch of complex analysis to students and the mathematical community around us.