FOSS as defined by Wikipedia

Before one goes exploring what FOSS (Free and Open Source Software) is, it is perhaps sound to look at the information that our trusted Wikipedia offers: http://en.wikipedia.org/wiki/Free_and_open-source_software.

Some basic concepts must be clear. One, software begins as a human-readable code that programmers develop. Two, this human-readable source code is then compiled into a binary format, the "language" that the computer's CPU can understand and execute. Three, the binary version of the code is the one that proprietary vendors sell, hiding the human-readable source code from users. Four, the Open Source community provides both the binary and the readable source code, so the user can learn, modify and adapt the code to her needs. What this means is that FOSS provides use, knowledge and generally a free product, while proprietary software provides use, but no knowledge of what different parts of the code do, and no way to correct, modify or update the code you paid for rented?.