The term "Open Source" is mainly used to describe free computer software, but recently it has been taken much further, into hardware, objects, and even ideas and politics. Lets take a look at the main philosophical differences between open and closed source:
Open Source
Generally synonymous with "free". Free means much more than just no financial cost. Free means that the products source (design or blueprint) is public. It is open; available to all. Everyone is free to to copy, modify and improve the product, even to make their own version and freely distribute that. As there are no financial incentives involved, the products main objective is to be user friendly, functional, compatible and last as long as possible. The main clause in the open source license is that if you use open source work in your products, then your products must also be open source. As no money is involved, there are no funds to pay for advertising, so unfortunately open source products generally stay unknown to the masses. Improvement is profit.
Closed Source
Generally synonymous with "proprietary". Closed source means that the products source (design, code or blueprint) is a trade secret. It is closed; copyrighted or patented. Only the corporation who "owns" the product knows how it works and has full say over design, manufacturing, updates and reproduction. Financially this makes a lot of sense, only the company can profit by selling pricey spare parts, repair and maintenance services, upgrades and add-ons, and it will usually not be compatible with other competing companies products. Basically it ties the customer into being dependent on the company. The downside of this is that the main objective is usually to lock you in and make a profit, rather than being designed to do an efficient, economic, and functional job. No one can improve this product other than the manufacturer. The more problems you have the more likely you are to call expensive help lines or order spare parts. These products can be designed to break down just weeks after the guarantee expires to increase repeat sales. Waste is profit.