A common misunderstanding is that apart from something to indicate severity, is that MESSAGE and ERROR have the same properties.
They differ in when they disappear having displayed their text to the user.
An ERROR will disappear at the next user interaction.
A MESSAGE will remain for longer and disappear when the window is closed or is overridden with the next MESSAGE. For that reason you may see MESSAGE "" in your code to make the message disappear.
Read more at
https://4js.com/ask-reuben/ig-163/