Chat technical support is a form of technical support delivered via online chat. Online chat refers to a kind of communication over the Internet that offers an real-time direct transmission of text-based messages from sender to receiver. wikipedia.org

Phone technical support refers to a range of services by which enterprises provide assistance to users of technology products such as mobile phones, televisions, computers, software products or other electronic or mechanical goods via telephone.

Search engine optimization (SEO) is the process of improving the visibility of a website or a web page in search engines via the "natural" or un-paid ("organic" or "algorithmic") search results. wikipedia.org

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

Customer service is the provision of service to customers before, during and after a purchase. wikipedia.org

A strategy employed by an organization in which a continuous level of engagement is maintained between the organization and its audience. Relationship management can be between a business and its customers (customer relationship management) and between a business and other businesses (business relationship management). wikipedia.org

Telemarketing (sometimes known as inside sales, or telesales in the UK and Ireland) is a method of direct marketing in which a salesperson solicits prospective customers to buy products or services, either over the phone or through a subsequent face to face or Web conferencing appointment