System Administration is, in essence, the integration of diverse vendor products into a working business solution. Five corporations could all buy identical hardware and software, and yet each site would be entirely unique. System administration is the point where all of the disparate needs and characteristics of the hardware, software, network, users, corporate policies and business environment collide.
System administration is about intricacy - the complex interplay of large interrelated components. System administrators deal with volumes of highly technical information, hundreds of products, thousands of commands and the individual, changing needs of corporations, departments, users and customers.