Way back in 1977 when a working group on Distributed Systems at ANSI was asked to work on OSI Model ( Open Systems Interconnection Basic Reference Model ) - they had little idea that the concept of distributed systems would one day grow to create the mother of all 'distributed systems' - the Internet. Technically the internet is a massive network of hardware - but conceptually, its a platform (or a cloud if you prefer) upon which Software Services can run seamlessly making it transparent to the users, where the software is running, where the data comes from, which hardware is serving server cycles ... and so on. All this abstraction is possible today only because of the well designed OSI Model which separates the "Presentation" from data and network from the underlying hardware. The OSI model has also helped to come up with protocols like TCP which have made compatibility a non-issue when it comes to connecting computers across the world (which run on different hardw