Can I run the same Minecraft Account on Multiple Computers at the same time?

I am going to purchase an account for Minecraft Java Edition, however, I wanted to know if I could use the same account on multiple computers at the same time, so I could be playing Minecraft on my laptop and my little brother could be playing Minecraft on another laptop at the same time as me on the same account (this is for singleplayer not multiplayer).


Edit: This answer is incorrect. See fasterthanlight's answer.


Original post:

You can use a single account on multiple computers but not at the same time. Your brother can use it only while you are not playing.


You can play at the same time using different devices, on the same account. However, only one of those accounts can join public servers. The others must stay on singleplayer mode. Otherwise, you may get kicked, or even banned, from the server.