Best UNIX Resources
The UNIX system was created in 1969 by Bell Labs. The system has evolved into several computer systems that are UNIX based or are similar to the UNIX configuration, such as Solaris, Linux, BSD, and Darwin. UNIX was the primary system that helped shape the Internet. The system is issued primarily as servers and workstations because of the multi-user capabilities. The diverse UNIX uses kernel technology, the shell, and system configuration files.
Bash Reference Manual