I am wondering why do mathematicians categorizes some structures and called them filters , Nets?
In English, filter means: A porous material through which a liquid or gas is passed in order to separate the fluid from suspended particulate matter.
Is this meaning of filter correspond to that of mathematics? What is the reason behind calling filter as filter in maths? Is their any reason for naming Nets (the structure) as Nets?
Please, may be my question is somehow useless but I believe in understanding of how and why our mathematical structures are named that way.