CRM marketing is a system where you can manage all your contacts and relationships. It will help you to get references from them in future, and you can easily understand the history of that contact at that time. This is really used as a sales tool to streamline your sales team and help to close deals faster.
Digital Marketing is how you are marketing your business, service, or product through the web. It can be done through search engines, social media, and websites.
The way CRM marketing and Digital marketing are related. After the digital marketing efforts, the CRM manager should be capturing the leads that have been generated into a CRM marketing, so that one can nurture the lead and close the deal successfully.