Social network

A social network is a social structure made of nodes that are tied by one or more specific types of relatives, such as values, visions, idea, financial exchange, friends, kinship, dislike, trade, web links, sexual relations, disease communication or airline routes.
Social network analysis views common relationships in terms of nodes and ties. Nodes are the individual actors within the networks, and ties are the associations between the actors. Research in a number of academic fields has shown that social networks operate on many levels, from families up to the level of nations, and play a serious role in determining the way problems are solved, organizations are run, and the degree to which individuals succeed in achieving their goals.
In its simplest form, a social network is a map of all of the appropriate ties between the nodes being studied. The network can also be used to decide the social capital of individual actors. These concepts are often displayed in a shared network diagram, where nodes are the points and ties are the lines.

Calculator

A calculator is a machine for performing calculations. Although modern calculators often incorporate a general purpose computer, the device is calculated for performing specific operations, rather than for flexibility. Modern calculators are more convenient than most computers, though some PDAs are comparable in amount to handheld calculators.
In the past, some calculators were as huge as today's computers. The first automatic calculators were mechanical desktop devices which were replaced by electromechanical desktop calculators, and then by electronic devices using first thermionic valves, then transistors, then hard-wired integrated circuit logic. New calculators are electrically powered and come in innumerable shapes and sizes varying from cheap, give-away, credit-card sized models to more sturdy adding machine-like models with built-in printers.