Email marketing is directly marketing a commercial message to a group of people using electronic mail email. wikipedia.org

Business Marketing is the practice of individuals, or organizations, including commercial businesses, governments and institutions, facilitating the sale of their products or services to other companies or organizations that in turn resell them, use them as components in products or services... wikipedia.org

Email marketing is directly marketing a commercial message to a group of people using electronic mail email. In its broadest sense, every email sent to a potential or current customer could be considered email marketing. It usually involves using email to send ads, request business, or solicit wikipedia.org