If you watch Japanese tv or anime (or are paying attention in class) you've probably come across the Japanese word 皆さん (mina-san) meaning "all" or "everybody".
But what's the difference between みな and みんな? What's みなさま all about? And ... does it actually matter?
Mina means "everybody", and it's commonly used with "-san" on the end (the same suffix you put on people's names to be polite).
みなさん is often used when addressing a group of people, especially when they don't know either other too well or the situation calls for a slightly more formal greeting.
I find myself using みなさん a bunch at the beginning of term when welcoming students back and/or trying to get you all to listen to me.
As you might expect, YouTubers say みなさんこんにちは a lot too ("HI EVERYONE").
Check out the first five seconds of this video from Ari Keita:
You can't mix them up and use みんなさん though. That's technically incorrect.
Or you can even go more polite with...
In more formal situations, the -san suffix is switched up to the more polite/formal -sama.
Why does this matter? Well really, which word you use is going to depend on the situation.
Mina-sama is super formal and it would sound weird if you use it with your friends. Likewise, minna is pretty casual and might not be appropriate in a business setting.
A lot of gaining fluency in a language is about choosing the right word for the right situation.