What is Free Software?

Free software is primarily an ethical way of understanding 
software or computer programs. That includes both the production of programs such as its distribution and use. Thus, free software is not geared (nor exclusive) only to people capable of writing a program, or people who have businesses and thus is able to do business with computer programs. 
However, free software is related to the user as much as the developers or merchants. Or maybe even more, because it is the users' freedom of the only goal of the free software movement.
So the free software movement as a concept and making it 
grow and evolve as a concept (and movement) ethics. Many people are confused and considers the 
free software movement as a movement highly technical. While this may be true for other similar movements (eg, the Open Source movement) is not at all when we speak of free software.
But what is exactly the software free?. The definition held by the Free Software Foundation says that if a computer program is considered free software must comply with four freedoms and rights as central to the user of this program:
  • Users must have the right to use the program, 
    without restrictions, anywhere, anytime and as for what 
    want.
  • Users must have the right to study how the 
    program and, if desired, to suit your needs 
    specific.
  • Users should have the right to distribute copies to their friends, 
    employees, acquaintances, employers and, finally, to anyone 
    wish.
  • Users should have the right to improve the program, and publish 
    distribute their improvements to the public (or those who wish) so that 
    more people leaving benefit from the changes.
Many people ask why it is so important to us that 
the user with these rights, to the point of mounting a 
movement and an integral part (and working!) hereof. Without 
question that requires an explanation, we present here reviewing 
right by law.
 
The right to use
The first right or freedom, which is about the right to 
use software, you may be surprised. Is not the people 
right to use a program that has bought in a store, for 
example?. The answer is that when a person "buys" a 
computer program is not free software 
(exclusive programs, we call them) do not generally
has the unlimited right to use that we 
consider inevitable: the user is limited to using the 
program for specific purposes (not to use this 
a commercial program) or in certain places 
(Forbidden to use this program in the country X and country Y) or 
a certain number of machines (not to use this program 
in more than one machine at the same time). These restrictions 
are very common when we talk about software, and we 
that are unacceptable. That is why we emphasize the right to 
use: it is constantly violated by the companies and enterprises 
that manufacture and distribute software.
 
The right to understand
On the other hand we have the second release for the user: the 
right to understand how the programs we 
distributed, and adapted to our needs. Again, this 
fundamental right is violated when the software 
talk: Usually, the software is distributed in 
executable form (equivalent to the files. "exe" environments 
Windows) to accompany you without the source code
concerned. The source code of a program is its 
form understandable and modifiable by the programmer. In 
some ways, is like the instruction manual for any device. If 
buy a universal remote control, set at the factory to 
our TV, and does not come with instructions, we will not be able 
use in our other TV in the kitchen. By 
contrary, if we have access to instructions, we can tune 
command as many TVs as you want. This is 
artifacts that we use to adapt to our needs. In 
For computer programs, we need the code 
source.
 
The right to distribute
From here we go right to the third or freedom: the right to 
distribute software for free, or 
alternatively, gaining something in return for doing so. This is perhaps 
better understand the point that users of private programs 
when they want to learn about free software. It is natural, since 
the software industry makes continuous efforts to 
try to convince the company to copy programs 
computer is not something that should be done. We, on the contrary, 
think that can be copied without the need of large resources 
(with just a recording unit) and the characteristic of 
that the copy does not lose quality from the original is not a bad thing: 
by contrast, is almost the best thing that has the software. Copy 
computer programs and distributing them is something that benefits the 
society. It is common sense. Make copies of programs 
private is illegal in most countries. So 
provide free software is perfectly legal to copy it. Of 
This way both the user and society benefit, and nobody 
loses out (the original copy does not work for making it worse 
or a million copies). It is an important detail: the software 
free is not necessarily free. It is perfectly possible 
distribute free software in exchange for money. This is how it can 
livelihood programmers and distributors. However, that 
fact does not justify violating the rights of the people who pay 
to obtain a copy of the program: the user can distribute their 
own copies, thus becoming, if desired.
 
Right to improve
The last right or fundamental freedom, the right to 
improving and distributing software upgrades, which is perhaps 
more controversial. Obviously, the user software 
privative can not improve the software you use: although 
and I knew I would do it, do not generally have access to the code 
source. And although I had (the video can be distributed and 
however not be free software) would be illegal to modify this code 
source. However, free software is always distributed with your 
source code, and it's perfectly legal to modify it. The objection 
Typical of this right is usually: "Well, okay, I have the code 
source. But I will not change for improvement. What I need 
then take it. "The answer to that question (and very rare 
understandable) is that to improve or modify a program is not 
necessary to do so yourself. In the same way that a person can 
take your car to a shop to be repaired (or will be introduced 
some improvements) and the workshop can do you like the most 
(the manufacturer of the car can not put restrictions) user 
software must be able to hire a professional (or a company, or 
ask your cousin the computer to do it for free) to improve the 
free software you have purchased or downloaded from the Internet. If 
the same user download or purchase software and want to 
better, then depends entirely on the company that sold you 
(or provided via the Internet) program. If the company decides that 
improvements desired by the user are not profitable or are not 
desirable for some other reason not to incorporate 
schedule. The result is that the user software 
always lose. With free software, by contrast, the user is 
free and is not tied to any company or enterprise. In addition, the 
user can distribute a program that incorporates improvements 
free or for a fee (this applies the third law explained 
above). And another important thing: the user also has 
right not to distribute their improvements if they do not want. A person 
can buy or download free software improvements, not 
redistribute or make such public improvements.
As we have seen, these four freedoms or rights to 
call the fundamental freedoms of software users 
books are not random or capricious: it is a concept 
very thought whose only goal is to make the corporation is jealous 
their rights when buying or download programs 
computer.
 
Article extracted from GNU Spain
Attached is a conceptual map of free software, from the same site, which summarizes in a single scheme and many of the concepts involved in this scenario.