What is the Meaning & Definition of functions

The concept of functions, and its singular function, usually it used extensively in our language and refer issues. To own something or someone's activity is the express through the word function. Maria, who works as a Secretary in a company, for example, has among its labor functions the attend telephone calls from his boss. Take message to caller if it is not, or let the call if it is.
Meanwhile, in biology, they are called as functions to those processes that take place inside the body of human beings, animals and human beings, and have the Mission of conserving the species in question.
Among the most important functions are: play functions (are those that facilitate the creation of a new agency, being the most common types of sexual, asexual, generative and vegetative), the functions of metabolism (which consist of reactions and processes that happen in the cells and the body and allow the cellular activity, are breathing) (, feed, among others) and the functions of catabolism (which is the branch of the metabolism that transform complex biomolecules in single pairs and in stored chemical energy that emerges from the links of molecules with high energy).
On the other hand, in the field of theatre, is called function to the representation of a play that the actors perform in a specific environment as it is the theatre. They perform it live. Similarly, when it displays a movie at the cinema refers to function. The entry of minors is forbidden in the night function.
In Linguistics, we also find a reference to the word given that function is the role played by a syntactic element, lexicon, or audio, on the structure of a sentence.
In the area of mathematics, it is called as mathematical function to the relationship that arises between two magnitudes and then to each of the values shall be responsible for a certain value of the other variable.