What is a unit?
Suppose, choosing yourself a slow cooker, you read in the product description that such and such a model is a rather complicated technological unit. What is a unit?
Translated from the Latin language, aggregatus means "assembled, connected." Most often, the term "unit" is used in the technical field. Here it denotes either a complex machine unit, consisting of a large number of individual elements, or a set of machines combined into one technological chain.
In mineralogy, for example, aggregation of minerals is called aggregate, in economics, the final result of individual economic operations, in the theory of information processes, a mathematical model with a high degree of generalization.
Assembly as a machine unit
The technical unit in the composition of the machine is designed to perform any one specific function. Examples of units are the engine, fuel pump, etc. Units are always interchangeable. That is, you can remove one unit from the machine and put a similar one in its place, while all the other components of the machine can remain old,and she will continue to work again.
The unit as a set of machines
Here, as an example, we can consider the operation of the pipe-rolling unit. The pipe-rolling unit is a system of rolling mills, some of which heat metal blanks-blanks, others stitch (they make round longitudinal holes), some of them roll out, calibrate, rule, cut off the ends. And at the exit it turns out finished pipe rolling.
There are also machine and tractor units.