Additional Insured

I'm thick headed sometimes. Our insurance guy asked me if I ask ours subst add us as additional insured to their policy. I first encountered the concept of AI like a decade ago and have never had someone give me a good explanation of what it actually means.

Any of you chaps know what it really is? Do you make a good habit of making sure everyone around you has it?

love
nick

Call me if you want, too much to write