The book attempts to provide the history of development of computer in stages, the structure of computer, the C language in detail in a simple and informative style and discusses various features of C languages systematically.It discusses a clear demonstration of operators, control flow, arrays, functions, strings, structures, union and bitfields, pointer and console-file.A large number of useful well-developed problems, about 166 in number have been presented at various locations to show various features of the language. A chapter which deals with number system which are very important to know basics of computer system.A large number of probable questions in each chapter will help the reader to build up his/her confidence on C. The presentation of large number of objective type questions with answer will help to test the knowledge on C.The book also contains all the DOS and UNIX commands with their use in advanced programming. A project on graphics also has been given to show the beauty of C language.The book will be of great use to the students of B.Tech, B.C.A, M.C.A, M.B.A, B.Sc, M.Sc and Diploma in Engineering and also to self learners of C.