How does my credit score affect insurance?

I’m trying to understand how my credit score affects insurance. Can someone explain how insurance companies use credit-based insurance scores when setting premiums, and which types of insurance are impacted the most (auto, homeowners, renters, or life insurance)? I’d also like to know how much of a difference a good vs. poor credit score can make, whether improving my credit can lower my rates over time, and if there are any states where credit scores aren’t allowed to be used. Real experiences or examples would be really helpful