Twins are tw0 0ffspring pr0duced by the same pregnancy.

Twins are tw0 0ffspring pr0duced by the same pregnancy.
Twins can either be m0n0zyg0tic (“identical”), meaning that they can devel0p fr0m just 0ne zyg0te that will then split and f0rm tw0 embry0s, 0r dizyg0tic (“fraternal”), meaning that they can devel0p fr0m tw0 different eggs, each are fertilized by separate sperm cells.


In c0ntrast, a fetus which devel0ps al0ne in the w0mb is called a singlet0n, and the general term f0r 0ne 0ffspring 0f a multiple birth is multiple.