While it isn't a compulsory insurance, fleet motor insurance is designed specifically for commercial vehicles — which is how it is different to regular run-of-the-mill motor insurance and also how it might be relevant to your business.
If you own vehicles that you or other employees use as part of your business, it goes without saying that those vehicles should be insured in some form or another. However, fleet insurance might be of particular value to you as a business owner as it often comes with benefits and savings.