Selling technique is the body of methods used in the profession of sales, also often called personal selling. 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

Time management is the act or process of planning and exercising conscious control over the amount of time spent on specific activities, especially to increase effectiveness, efficiency or productivity. 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