Some infos have been removed due to plagiarism. Please do not directly copy paste any text from external sources.

About

The GNU project is a Free (libre) movement that was launched by Richard Stallman in 1983, having the goal of giving the users freedom and control in their use of their computers.
GNU stands for "Gnu's Not Unix".

Freedom and Liberty of Creation

The "freedoms" as said are simple liberty rights, when you have a car you have the right to disassemble it if you want too study it or anything you want to, but in the computers world most of the computers sold are not respecting simple consumer rights, the most common example is the per default integration of Microsoft windows OS in the computer.

-The freedom to run the program as you wish, for any purpose (freedom 0).

-The freedom to study how the program works, and adapt it to your needs (freedom 1). Access to the source code is a precondition for this.

-The freedom to redistribute copies so you can help your neighbour (freedom 2).

-The freedom to improve the program, and release your improvements to the public, so that the whole community benefits (freedom 3). Access to the source code is a precondition for this.

Free as in free Beer ?

A lot of people thinks that free software is free of charge and wants the software's to be with no charge (gratis) this was never stated by the free software movement some free software's have charges an example is Red Hat linux who sells support and not the software.
The free software's movement only cares about the Freedom of use.

The Free Software Foundation

The Free Software Foundation is a non profit organization founded by Richard Stallman.
The FSF is the publisher of the GPL licence

The GNU/Linux naming controversy

Most people unfortunately refers Linux as the whole operating system.
In reality Linux is just the kernel (it manages resources (ram, load etc…)of the pc).
GNU is not only some sort of ideology but it's also a compilation of programs and when the project was almost done only one thing was missing, the kernel.
The kernel of GNU called HURD began is development in 1990 (one year before the release of Linus Torvalds "Linux" kernel)
With the release of the Linux kernel (started independently by Linus Torvalds in 1991) and released under the GPL licence in 1992, for the first time it was possible to run an operating system composed completely of free"> software.
Though the Linux kernel is not part of the GNU project, it was developed using GCC and other GNU programming tools and was released as free software under the GNU General Public License.

GNU/Linux distributions

There is a lot of existing distributions but there are actually two kind of GNU/Linux OS.
The ones with completely free software's and the one with a bit of propriatory software's.
What's the difference you thought that all gnu was supposed to be free ?
well yes but there is a fact to most users don't know the firmware issue.

Firmwares is a type of software that provides control, monitoring and data manipulation on electronic devices.
And most of the code of these firmwares are closed by the constructors.
An example of firmware is the BIOS, we can also find firmwares in ABS, washing machines, phones, alarms, even modern fridges.
A packaged non-free firmwares in a GNU/Linux OS is called a BLOB
So actually the GNU/Linux world is divided by the ones who allow proprietary softwares in the OS and the others who do not allow any of them.

Free Software's and Open source

In free software the GPL licence states that you have the right to read/modify the code and thus have to access the code, so the code needs to be open source to be at least readable.
Some people only release there code as open source.
Open source software doesn't protect the users, an example is if someone use the code of a open source project, that said someone can legally close the source of what he did, it simply goes against the share and learn philosophy of GNU.

External References

Richard Stallman
GNU
Free Software Foundation
GNU Philosophy
kernel
GPL an other licence