Taxon.
The general term for any level in a taxonomic system is a "taxon." Taxa can range from broad categories like kingdom to specific categories like genus or species, depending on the level of classification being considered.
There in no term limit on this Cabinet-level post - they serve "at the pleasure of the President."
A general definition of the term "professional" is somebody who does something at a level where they are qualified to do it, and are paid accordingly.
Grant-in-Aid
Inflation
operating system
The general term for large-scale evolutionary changes that take place over long periods of time is macroevolution. It refers to the processes that result in the formation of new species and higher taxonomic groups.
The term you're looking for is "taxon," which refers to a group of organisms at any level of a taxonomic hierarchy. Each taxon has a formal name based on a classification system that orders and ranks organisms based on shared characteristics.
operating system
Inflation describes a sustained increase in the general level of prices over a period of time, resulting in a decrease in the purchasing power of a currency.
What exactly do you mean by 'optimal operating system'? If you don't define the term there is no way to answer the question.
distributed system is a special case of computer network.ofcourse distributed system is a network but a network may or may not be distributed.In general,a computer network is a very general term but distributed system is more specific..