What Are Servers

Servers are computers which typically support multiple users. As with all computers, they contain processors, memory, networking and data storage capabilities. Servers come in various shapes and sizes. At high level, servers fall into three categories:

1 Mainframe (proprietary)
Often dedicated for specific, enterprise wide tasks, mainframes are the grand-daddy of servers. Based on a monolithic architecture, mainframes consist of hardware and software which is often provided by a single vendor - or perhaps by two vendors who are almost entirely reliant on each other. The lock-in between hardware and software is the very reason why mainframes still exist today and less costly alternatives have not ousted them. The sheer cost of developing alternatives and the costs for customers to change away from systems which are tightly embedded in their business processes - means they are here for some time yet. Mainframes today represent a very small part of the total server market.

2 Unix (open systems)
In order to break the stranglehold of mainframes and to lower the cost of computing - Unix based systems were born back in the 1970s. Unix refers to the open standard operating system (software) that runs on these computers. Originally developed by AT&T then enhanced by many University under-graduates, the system broke the link between hardware and software, increasing competitiveness and reducing costs. However, as Unix evolved, new companies were set up to commercialise the new systems and provide business solutions based on combinations of hardware and software. This process led to proprietary versions of Unix evolving. Today, Unix systems represent just under half of the server market in terms of revenue but are seen as costly compared to the third category of server which evolved from the first PCs in the 1980s.

3 Industry Standard (open systems)
The first PC was produced by IBM in 1981. Consisting of an Intel processor and chipset and storage controlled by a disk operating system called MS DOS (how original). The MS stood for Microsoft - Bill Gates' most significant software release ever. PC stands for Personal Computer - the exact opposite of a mainframe in that for the first time, users could have their own personal computing environment - on their desk. IBM made the decision to open up the fundamental design of the PC so other manufacturers would help establish it as the industry standard.

As PC's evolved, it quickly became apparent that connecting them together could be useful. Data could now be shared. The natural progression of this was to have perhaps one PC with a big hard drive - to hold data for others to share. The first industry standard server was born.