Interaction; reciprocal relationship.
To interact.
A group of entities, such as objects, that interact together.
Any combination of cams, gears, links, belts, chains and logical mechanical elements.
Any process of, or system designed to manage useful energy conversion.
A mental, physical, or chemical process.
The theory that all natural phenomena can be explained by physical causes.
Any mechanical means for the conversion or control of motion, or the transmission or control of power.