CGMINER and LW: what does it exactly mean?

[ANJULE]

So I get tons of LW: meaning Locally Generated Work Items.
I have searched for two weeks now and found one occasion that said it to be really good thing.
But nothing more. Nothing that explains it "goodness" or where does it come from.
I didn't found anywhere it to be a bad thing.

I'm interested about the origins of LW.
So is the LW a good thing, where does it come from? What setup encourages it to generate?
Please give me as much info as possible as detailed as possible.

Thank you for your time and efforts.