What is the difference between "free-as-in-speech" and "free-as-in-beer"?
"Free as in free speech" vs "Free as in free beer" isn't a concept, it is an example of a concept. :-)
This example belongs to the GPL and is used to clarify the definition of "free" in the term "Free Software".
Free beer is gratis. It doesn't cost you anything. The term refers to the price of a product. This is not the intention of the word "free" in this context.
The intention is more like "free" in free speech, the liberty to say the things you want without getting censored.
"free" is ambiguous in English, and FOSS people tend to mean the former when people misinterpret it as the latter, which is why the phrases came about
- free as in speech means freedom; in an open-source context, the license doesn't prevent you from fiddling with the code or making your own changes
- free as in beer means price; the software costs nothing
There was (is?) a lot of confusion when people said they support "free software" -- free (as in speech) software doesn't need to cost nothing, and costing nothing doesn't necessarily make software "free".
As I mentioned in the comments here, I e-mailed Mr. Richard Stallman about this. Here is his reply:
From: Richard Stallman
Date: Fri, Oct 22, 2010 at 9:12 AM
Subject: Re: “free-as-in-speech” vs. "free-as-in-beer”
To: RENJITH G
QN: I would like to know the exact meaning of "free-as-in-speech" and "free-as-in-beer"
It is hard to give "exact" meanings for philosophical concepts, so I am a bit lost.
The English word "free" has two different meanings. Many other languages have different words for them. For instance, I think Hindi has "mukt" for "free as in freedom" and "muft" for "gratis, zero price'.
QN: Also why this example words (the words free-as-in-speech and free-as-in-beer) are being used to descibe the concept?
Those are not the words I use. I use "free as in 'free speech'" and "free as in 'free beer'". Is that clearer?
It seems you heard someone else shorten the two phrases a little.
President, Free Software Foundation
51 Franklin St
Boston MA 02110
'Free' word used in the context of Free-speech. Free-speech itself is used very liberally as it's literal meaning could be quite misleading (esp to non-American). So to narrow it further take "Free-speech" as the one of the fundamental rights enjoyed by every US citizen as per US Constitution.
So the 'free' word in 'free software' stands that grand not only to the level of not paying for the software only.
I think everyone else has already accurately described - free as in beer concept. So I wouldn't repeat.
As mentioned in other answers, the English word free is ambiguous, because it can represent two different concepts.
The mayor issue with mixing up the two concepts is that you can have one without the other. And more importantly, no sane person would choose one over the other.
"Knowledge is freedom, Ignorance is slavery" - Miles Davis "Emancipate yourselves from mental slavery" - Bob Marley
These are not less true in software. If I and I have the source code of a program, then I and I can study it. If I and I can change it, then I and I can break out of whatever handcuffs it tries to put on us. If I and I can share the corrected software with fellow humans, then no one would use the malicious one. Therefore it would not even worth the effort on the long term, to try creating a malicious one in the first place.
Richard Stallman often uses the words libre and gratis, which in Spanish/French (Latin origin) correctly represents the two separate concepts. For the same reasons, instead of the acronym FOSS, using FLOSS is highly recomended. In fact if you keep reminding yourself of this daily, it will even improve your dental health.