Cold calling is the marketing process of approaching prospective customers or clients, typically via telephone, who were not expecting such an interaction. wikipedia.org

A sale is the act of selling a product or service in return for money or other compensation. It is an act of completion of a commercial activity. wikipedia.org

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

Lead generation, or lead gen is a marketing tool used, particularly in internet marketing, to generate consumer interest or inquiry into products or services of a business. wikipedia.org

A data entry clerk, sometimes called a typist, is a member of staff employed to type data into a database using a keyboard. The keyboards used can often have specialist keys and multiple colours to help them in the task and speed up the work. 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

A sale is the act of selling a product or service in return for money or other compensation. It is an act of completion of a commercial activity. wikipedia.org

Customer relationship management (CRM) is a widely implemented strategy for managing a company's interactions with customers, clients and sales prospects. wikipedia.org

Customer support is a range of customer services to assist customers in making cost effective and correct use of a product. It includes assistance in planning, installation, training, trouble shooting, maintenance, upgrading, and disposal of a product. wikipedia.org