Can anyone explain what Kanji Variants are? How are they different from kanji without Variants? What are they used for? I don’t know anything about them at all. I can’t find an explanation anywhere. I don’t know what they do ether.

See a translation

I can’t write all of sentence in English.
But I found out article about it.
This sentence is translated by google.

In fact, even though the meaning and pronunciation are the same, the kanji with different characters comes from the prototype of kanji, which was born in China about 1600 BC.

What does this mean? Different characters are born mainly because they are handwritten. If it's handwritten, it's natural that the strokes are short or long, suppressed or paid, and the expression changes depending on the person. When there are letters that have been used until then, it is written in a slightly different way, and it does not disappear as a typo, but many people start to write like that and take root to some extent ... Moreover, the previous way of writing is also alive ... This is the source of different characters. "Styface", which is a style of kanji such as Kaisho and Gyosho, is also involved.