Linux for beginners

 In  this course we are going to learn 3 sections:

1)Linux Basics

2)Linux Network Administration

3)Linux Server Administration

Linux Architecture:

• Hardware − Hardware consists of all physical devices attached to the System. For example: Hard disk drive, RAM, Motherboard, CPU etc.
• Kernel − Kernel is the core component for any (Linux) operating system which directly interacts with the hardware.
• Shell − Shell is the interface which takes input from Users and sends instructions to the Kernel, Also takes the output from Kernel and send the result back to output shell.
• Applications − These are the utility programms which runs on Shell. This can be any application like Your web browser, media player, text editor etc.

References:

https://www.geeksforgeeks.org/introduction-to-linux-operating-system/

https://www.elprocus.com/linux-operating-system/#:~:text=Linux%20System%20Architecture,library%2C%20Shell%20and%20System%20utility.

Linux Directory Structure:

1)bin - It stores all system library files.

2)boot - All the files related to booting the system are stored here.

3)dev - This directory contains special files (device files) corresponding to physical devices or system components.

4)etc - All configuration files resides here

5)lin and lib4 - All library files used by binary files resides here.lib64 contains 64 bit and normal lib 32 bit libraries.

6)media - It is a regular directory which by common practice is used to mount removable media like CD-ROMs, floppy disks, etc.

7)mnt - is a regular directory which by common practice is used to mount other filesystems, usually for a short period of time.

8)opt - for installing optional applications

9)proc - filesystem providing process and kernel information as files

10)root - This is root users home directory.Only root user will access it.

11)run - The /run directory is fairly new, and gives applications a standard place to store transient files they require like sockets and process IDs

12)sbin - It stores all super user binary files.

13)srv - It stores service related information.

14)sys - It stores system related files.

15)tmp - Directory that contains temporary files created by system and users and Files under this directory are deleted when system is rebooted.

16)usr - Secondary hierarchy for read-only user data; contains the majority of (multi-)user utilities and applications.

17)var -  Log files and everything else that would normally be written to /usr during normal operation are written to the /var directory. 

References:

https://www.howtogeek.com/117435/htg-explains-the-linux-directory-structure-explained/

https://www.thegeekstuff.com/2010/09/linux-file-system-structure/

https://www.geeksforgeeks.org/linux-file-hierarchy-structure/ 

User Administration:

To create and delete users: click here & clear explanation video by 7Hills:click here

File permission changing using chmod: click here & clear explanation video by 7Hills:click here

ACL permission for files: click here & clear explanation video by 7Hills:click here