What is Commercial General Liability Insurance for tenants?

I am assuming you mean a tenant in a commercial building as opposed to a residential tenant (i.e. apartment dweller). A tenant in a commercial building will typically be a business of some sort (eg. a Retailer located in a shopping Mall, or a manufacturer who rents a warehouse or plant, etc.). Whatever the case, it is important for a commercial tenant to be properly covered by a Commercial General Liability (CGL) policy which will provide protection against claims for Bodily Injury or Property damage caused through the negligent actions of the Tenant/Business. A prudent Landlord will require all of his/her tenants to carry CGL coverage and will seek to be added to the policy as an "Additional Insured". This will help protect the Landlord from lawsuits brought about by the negligence of his/her tenants. Hope this helps.