1. Understand Machine/Computer

 1. Understand Machine/Computer

• What is Machine

The computer is machine and machine is something that takes input, process and then give us output. 

E.g.

• Water heater is machine which takes water as input and gives us hot water. 
• Sugarcane juice machine takes sugarcane and gives us Juice and waste as output. 

    Computer is also a machine that takes input from user and displays output on screen. But the heart of computer the CPU takes electricity as input and gives us back electricity. 

We convert electricity into screen and show output. 

Input to computer is given using Keyboard/mouse or other human operatable devices. These device convert human input to electricity and provide it as input to CPU. 

Lot of hardware/software take place in between human and CUP. 

• Hiding the complexities of hardware from the user.
• Managing between the hardware's resources which include the processors, memory, data storage and I/O devices.
• Handling "interrupts" generated by the I/O controllers.
• Sharing of I/O between many programs using the CPU.

OS is platform where other softwares be run. This makes it easy for developer to not worry about hardware. And also it allow end user to provide interface to run Application software. 

GUI(Graphical User Interfaec) made easy for end user to access computer. GUI was key factor in groth of computer uses. 

• Linux OS

Many different OS have been built for different purposes. Some of them are GUI some of them may not have GUI interface. 

E.g.

• MS DOS was command line OPERATION system. 
• Windows XP, 7, 8, 10…. Are GUI Operating system. 
• Mac OS is also GUI os from Apple. 
• Linux on other hand is Open Source operating system. Which means Linux was built by community. By linux it means Linux kernel which itself have not GUI or command line interface. 
• Android is OS made by google to run on Mobile devices. Android uses Linux kernel. 

Linux itself is kernel only. Kernel can’t be used directly by end user. Many different tools applied over then kernel then you get OS like Ubuntu, Red Hat, Fedora, OpenSUSA…    

• Command Line Interface

The command line interface is a text-based interface to interact with the computer. It takes text as a command based on the given text computer runs the program associated with the command and provides the output.