LINUX

1. System

1.1. It includes System libraries, which helps in implementation of the functions of operating system

1.2. It consists of various modules and it directly interacts with the kernel devices

1.3. It provides user security using authentication features like password etc.

2. Licencing

2.1. It is distrubuted to GNU (General Public License)

2.2. It is free for anyone to modify,use or copy in any manner

2.3. The copyright for the code is held by the code's author

3. History

3.1. It was developed by Linus Torvalds.It was begun in 1991 as his personal project.

3.2. It has a monolithic kernel and it can dynamically load and unload kernel code on demand

3.2.1. Popular linux distributions are Debian,Ubuntu,Red Hat,Fedora and CentOS

4. Kernal

4.1. Linuxv1.x March 1994

4.1.1. Network implementation

4.1.2. Device Driver Support

4.2. Linuxv2.x March 19,2011

4.2.1. Support for IP sets

4.2.2. File system Pstore for analysing core crashes

4.2.3. Removing Big kernel locks

4.3. Linuxv3.x November 2, 2013

4.3.1. Security label support for NFSv4

4.3.2. It contains the block layer cache Bcache

4.3.3. Flash-Friendly File System integragted in the core

4.4. Linuxv4.x December 23, 2018

4.4.1. driver for 2.5-GBit-Ethernet-Chips from Intel

4.4.2. Common Applications Kept Enhanced (CAKE) algorithm

4.5. Linuxv5.x November 24,2019

4.5.1. Processes can be processed faster or more efficiently through "Scheduler Utilization Clamping" (Uclamp)

4.5.2. Performance improvements in the Storage-IO Scheduler BFQ