To the uninitiated: Open Source can be defined very specifically, but there is a lot of nuance that comes with the evolution of the theory, and with variables in the way that an author allows the use of code or words to paper. Generally, the formats developed in the last 2 years are better described and more easily understood. The definition given in the first paragraphs at Open Source Initiative is quite condensed, each word meaning a specific purposed concept. Let’s simplify a little and just say that Open Source software is software that has been developed by people who don’t want the copyright process to allow the code to become proprietary. The software is therefore open to any developer who would like to examine it, and typically, to any developer who wants to contribute to it.
A by-product of this is that the virtues, benefits, and flaws are in the open. Unlike with proprietary software, an enduser is able to see into the code, for example, to see if it leaves the users computer vulnerable, or if it really meets the specification as described, and without phoning home with vital information from the user’s network.