For certain professions, a license is necessary to show that you’re competent and permitted to conduct business in the city, municipality, or state in which the license was issued. For example, home improvement contractors will have to be licensed to perform certain types of work and that license number will be printed on every advertisement they print. You can take that license number and look up their performance history in most states through the Better Business Bureau.
This refers to what happens if someone gets hurt on the job. Let’s say a company is fixing your roof and a roofer falls off and hurts him or herself. If the company isn’t insured, then the claim gets filed against your homeowner’s insurance (bad). If the company is insured, then the claim gets filed against the roofing company’s insurance.