What is a rune in Go and how is it different from a regular byte?

I just started learning Go and came across a strange thing — the `rune` type. It seems to be an integer, but why have a separate type? I'm trying to work with strings and noticed that when I get a character by index, I get strange numbers instead of letters. Here's an example that confused me: ```go package main import "fmt" func main() { s := "Привет, мир!" fmt.Println(s[0]) // Prints 208, not 'П' fmt.Println(string(s[0])) // Prints 'Ð', not 'П' } ``` Why does this happen? I expected `s[0]` to give me the first character of the string. But instead I get some garbage. I read that I need to use `rune`, but I don't understand how exactly. I tried this: ```go r := []rune(s) fmt.Println(string(r[0])) // Now prints 'П' ``` This works, but I don't understand why.