This book describes how all these kinds of support are provided both by operating systems and by additional software layered on top of operating systems, which is known as middleware. The objective of this book is to make the students understand the basic operating system concepts such as processes, threads, scheduling, synchronization, deadlocks, memory management, file and I/O subsystems and protection.This note explains the following topics: OS Internals, C Programming, Bit-wise Operators, File Systems, Processes, File Descriptors, Threads, File Systems Internals, Synchronization,...