Basics Of OS

An OS is comprised of a number of pieces:

1.The Bootloader.
2.The kernel.
3.The Shell.
4.Graphical Server.
5.Desktop Environment.

Now we can describe the number of pieces show below:

The boot loader is a type of program that loads and starts the boot time tasks and processes of an operating system (OS) or the computer system.The boot loader is also known as a boot manager or bootstrap loader.
The boot loader primarily manages and executes the boot sequence of a computer system. The boot loader program is typically started after the computer or the BIOS have finished performing the initial power and hardware device checks and tests.
Since it is usually the first software to run after powerup or reset, it is highly processor and board specific.

Kernel is the central part of an operating systems. It manages the operations of the computer and the hardware most notably memory and CPU time.The kernel is the most fundamental part of an operating system.
When an operating system is loaded into memory, the kernel loads first and remains in memory until the operating system is shut down again. The kernel is responsible for low-level tasks such as disk management, task management and memory management

kernel is for:
* Process management for application execution.
* Memory management, allocation and I/O.
* Device management through the use of device drivers.
* System call control, which is essential for the execution of kernel services.

There are five types of kernels:

1.Monolithic Kernels.
3.Hybrid Kernels.
4.Nano Kernels.
5.Exo Kernels.

Daemon is a program that runs in the background without user’s interaction.A daemon runs in a multitasking operating system like UNIX.A daemon is initiated and controlled by special programs knows as processes.

Shell is a user interface for access to an operating system’s services. In general, operating system shells use either a command-line interface or graphical user interface, depending on a computer’s role and particular operation.

The shell is called a command interpreter. A shell usually implies an interface with a command syntax (think of the DOS operating system and its “C:>” prompts and user commands such as “dir” and “edit”).

Shell in Unix is a user interface that is used by a user to access Unix services.
Unix Shell is a command line interface (CLI) in which users enter commands

Graphical Server:
Computers until the rise of mobile computing.Desktop GUIs help the user to easily access and edit files, while they usually do not provide access to all of the features found in the underlying operating system.

A desktop environment typically consists of icons, windows, toolbars, folders, wallpapers and desktop widgets(see Elements of graphical user interfaces).A desktop environment aims to be an intuitive way for the user to interact with the computer using concepts which are similar to those used when interacting with the physical world, such as buttons and windows.

Types of Some Desktop Environment:


when Linux was considered the Operating system for geeks and nerds, for hardcore coders and developers. Linux operating systems now spot really beautiful and intuitive user interfaces and Distros.
You may be wondering what applications you should install. The following is a list of 50 useful and reasonably popular applications that many Linux users enjoy, in no particular order.