What is the Meaning & Definition of twins

The term twin or twins is used to designate those who because he was born of a same pregnancy share similar physical features and with each other can be confused. The twins are different from the twins by the fact that the latter are born of a same embryo while that the twins do not. However, both (both the twins and the twins) share the fact that are born all in a same gestation and are therefore quite special if you consider that the normal parameters for human beings is the birth of an individual by gestation.
When we talk about twins, it is important to make the clarification that allows us to differentiate them from those individuals considered to be twins. In medicine, the twins are the individuals who are conceived and born once an embryo or egg was divided in two and gave rise to two different bodies. The twins, on the other hand, are different embryos that take place in the same pregnancy and that, obviously, share genes but not so directly as the twins. In general, the twins tend to be much more abundant than the twins. While the latter tend to be two individuals in the majority of cases, the twins may be two, three, four and more even.
The twins have similar physical each other but just to not be a part of a same embryo are not identical as with the twins. This makes that, in social terms, it is easier to distinguish one individual from the other because although they share similar traits, each has their own distinctive traits. Even may be the case in which one of the twin brothers did not share similar traits with others and that stands out from the rest.