It refers to something like an object, element, person or animal that can be the same as the other in appearance, form or function, forming a pair becoming almost equal to these, such as the twin towers or when they are expressed from two people to the say they are two soul mates. Being an objective that with its usefulness both for the female and for the male can be used to refer to a person or an animal, as they are born from the same birth, especially when they develop in the same ovum, becoming identical twins; This is where the expression could come from saying that they were born together or are the same because of their similarities.
The human body has muscles called twins, because they are partners with each other, they are located in the lower part of the leg at the back of it, being both equal and even, their function is to help raise the heeland to be able to extend the foot; They are what we call the calf muscles. In the art of good dress and etiquette, they speak of a set of buttons with two loose pieces that in the same examples serve to close and adorn the cuffs of shirts, it is an ornament that man uses as part of his clothing to give more elegance and style to the dress suit, such as the handkerchief that protrudes from the pocket, they are made of various materials such as gold, silver, bronze or steel that some more are inlaid with precious stones such as diamonds, swarovski among others, they are sometimes personalized with the insignia of people's names.
Binoculars, binoculars and spyglasses are also known as twins, being an optical instrument that allows and helps vision at a great distance, formed by two identical cylindrical tubes joined together and that have magnifying lenses giving a greater magnification of the view either with one or both eyes, its function is to zoom in on objects, people or places from a distance. It is a word derived from the old Latin gemellu, coming from the same etymological origin as the word twin.