Process in Unix? Mechanism of Process creation in Unix? Process states and transition with diagram?

A process is simply a running program. A process is said to be born when the program starts execution and remains alive till the process is active. After the execution the process is said to be died.

Unix File System? Unix file structure? Blocks of Unix file system? Structure of regular file?

UNIX File System

Unix treats every thing as a file. All the utilities, applications and data are stored as a file. Even the devices and directories are also stored as a file. A Unix file system resembles an upside down tree. At the top their is root branching other directories called bin,lib, dev, usr, tmp, etc. Their is also a sub directories called UNIX which is nothing but a UNIX kernel it self.

Overview of UNIX architecture

Unix architecture

Unix OS divide into 2 parts : 

1. Kernel
2. Shell

Kernel:  Kernel is the heart of the Operating system.

Unix Operating system with its basic features

About UNIX:
Operating System is the system software that act as interface between computer hardware and application software. Ex: DOS, Windows, Unix etc.
Unix was originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie etc.