I have a question and as I don't practice "traditional" martial arts I'm looking to you guys to give me the answers.

We have various Kata that are practiced that have a "Dai" & a "Sho" variant to the Kata. What is the reason for this, are they completely different Kata or 2 Kata created from one major Kata.

The Kata that follow this concept that come to mind are:

Bassai Dai & Bassai Sho
kanku Dai & Kanku Sho
Gojushiho-Dai & Gojushiho-Sho

And Albeit a few others that some could add themselves

A man is but the product of his thoughts what he thinks, he becomes.