Well, the word can mean many things.
The most famous one being a Nursery song called “Twinkle Twinkle Little Star”. Almost all children who attend kindergarten and nursery knew how to sing this song.
It can also means other things, such as the “twinkle”(flicking) of an eye.
The light can also twinkle, which means it shines with an unsteady light which rapidly and constantly changes from bright to faint.
Someone’s eyes can also twinkle, when they find that something is amusing or that they are being happy and delightful that day.