URL is an acronym for Uniform Resource Locator. Basically, it is the web address for a website. For example: the URL for this site is https://pinoak.net/.
A domain name is like your online street address. When you started your business, you went and got a business name and registered it. You had to use a mailing address for that business. A domain is the same thing, only it’s on the web. Example: microsoft.com