How the concept of computer change over time? There was a time when a &quot;computer&quot; was a person who worked on accounts. However, machines were introduced and this profession eventually died out over time. The definition below was taken from pag 750 of volume C of the year 1893 of the OED dictionary:

Computer [...] one who computer; a calculator, reckoner a person employ to make calculations in a observatory [...]
Oxford English Dictionary. Year: 1893; Volume C. Entry computer, pag 750.

People today attribute the concept of a computer to a machine. Some even think it is wrong to say that human beings &quot;compute&quot;, because in their head computers are only &quot;machines&quot;. Historically we know that this is not true and commenting on this mistake is the same thing as: finding that humans are not animals, because humans are not chimpanzees.
An oberservation that I believe to be unnecessary, but it may prevent some people from making some mistakes. Human beings are not machines. I say this not because humans have feelings and machines do not, people think that way are thinking wrong. Because machines are physical objects designed by some intelligent being as a means to achieve some purpose. If you stop to think, all machines are like that and in principle nothing prevents us from having a machine that has feelings since they can be made of the same atoms as us and have structures as sophisticated as ours. Perhaps in the future, with genetic engineering, the distinction between machines and living things does not make any difference. But, that's not what I'm discussing here.
My question is this: Why do many people today only assign computing to machines only? Why is it not commonly accepted today that human beings are also computers? Since the first computers were human?
The Online Etymology Dictionary gives the first attested use of
  "computer" in the "1640s, [meaning] "one who calculates,"; this is an
  "... agent noun from compute (v.)". The Online Etymology Dictionary
  states that the use of the term to mean "calculating machine" (of any
  type) is from 1897." The Online Etymology Dictionary indicates that
  the "modern use" of the term, to mean "programmable digital electronic
  computer" dates from "... 1945 under this name; [in a] theoretical
  [sense] from 1937, as Turing machine".


It seems the word computer was given a new definition in 1945 to the more familiar programmable computer we think about today. Words change meanings all the time, it's the evolution of language and as machine computer became more popular than human computers the term computer changed as well. 

Technically anything which can simulate a turning machine can be considered a computer so humans naturally can also be considered computers, but that just seems more confusing than it is helpful.