Multiuser: A multi-user Operating system allows more than one user to share the same computer system at the same time.

Multi-Tasking: More than one program can be run at a time. The main concept of multitasking is maximum utilizing CPU resources

Open System: The UNIX is open source code i.e Any user can modify Unix open-source code according to there ideas and requirements

  • Using UNIX open source codeSun Micro Systems+ Adding additional features =Sun SalariesIBM+Adding additional feature  =  IBM-AIXHP+Adding additional feature= HP=UXSunta Curuz + Adding additional feature= SCO-UnixSilicon Graphics   +Adding additional feature=   IRIXMicro Soft+Adding additional feature  =    xenix
  • Any operating system developed based on UNIX open-source code known as flavours of UNIX
  • The Linux was given to GPL (General Public License) Organized by GNU.
  • Linux Torvalds, who was then a student at the University of Helsinki in fin land, developed Linux in 1991. Linux is also an open system

Distributors of Linux

  • Red Hat
  • Suse
  • Ubuntu
  • Puppy
  • Slakware
  • Centos
  • OEL
  • Fedora
  • White box
  • Mandrake

Inclined to build a profession as Linux Developer? Then here is the blog post on, explore Linux Training

Security: One of the most valued advantages of Linux over the other platforms lies with the high-security levels it ensures. Every Linux user is happy to work in a virus-Free environment and use the regular virus prevention time needed when working with other operating systems for another more important task.

--> UNIX/LINUX has given two levels of securities.

  • System-level Security: It's controlled by the system administrator.
  • File-level Security: It's controlled by the owner of the file.

Portability: Portability means Independent of hardware & processors

Communication: The main concept of communication facility Exchanging of information or files from one user account to another user account.

Programming Facility: UNIX o/s provides shell. Shell works like a programming language. It provides commands and keywords.

Script LanguageProgramming Language
It is an interpreter based language.Compiler based language
Interpreter Converts high levelThe whole program in a single short into machine language.
Doesn’t create .exe filesCreate .exe files
No need to compile the program.Need to compile the program
It takes less lines of codeTakes numerous lines of code.
Reduces cost of maintenanceIncreases cost of maintenance.

Help facility: It is the beautiful feature of UNIX/ LINUX Operating systems. Don’t know the information about given command just go through the helpline.


#Man <command name>


­­­­ #info <Command name>


#<command name> --help


Linux Interview Questions


For an in-depth understanding of Linux click on