What are the "Unncessary logs"?

Avast Free Antivirus / Premium Security
1

Avast antivirus says that my mac running Mojave has 1.25 GB of “unnecessary logs”:

https://i.stack.imgur.com/09A5d.png

The Avast website and forum do not provide information about their meaning.

What are they?

2

→ https://forum.avast.com/index.php?board=5.0