Twins or twins
As everyone knows, there are kids who are born the same, but are completely different. And this depends on how many oocytes the spermatozoa meet at the time of fertilization. If the female cage was one, then these babies are called a monogamous twins or twins. Such babies are born only of one sex and are born very similar.
And there are babies who are born when fertilizing several eggs. They can be of different sexes or same-sex, and absolutely not be alike. Such babies are usually called a double-twins or twins.
Bihorial biamnotic pregnancy in a woman can develop both in the first and in the second case, but only if certain features are observed.
Bihorial biamnotic twins means that crumbs develop in separate amniotic membranes, and each of them is attached to the uterine wall by its placenta.
If we talk about the identical twins, they are divided among themselves by the interfruit shell, which consists of several layers. Such babies are born much less than those that resulted from the fertilization of several eggs.
So, the conclusion of ultrasound that you have "bihorial biamnotic twins" is the early appearance of twins or twins. And they will look like "like two drops of water," or they will be different, depending on the type of twins they refer to.