Email marketing is a form of digital marketing that involves sending promotional, advertising, or informational messages to a target audience using email. It can be used to build brand awareness, promote products and services, retain customers, or generate leads and sales. Email marketing campaigns are typically created and sent to a list of subscribers who have opted-in to receive emails from the company. The success of an email marketing campaign is often measured by metrics such as open rates, click-through rates, and conversion rates.