Technical support or tech 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.

Office administration is a set of day-to-day activities related to financial planning, billing and recordkeeping, personnel, and physical distribution and logistics, within an organization. wikipedia.org

Microsoft Excel is a proprietary commercial spreadsheet application written and distributed by Microsoft for Microsoft Windows and Mac OS X. It features calculation, graphing tools, pivot tables, and a macro programming language called Visual Basic for Applications. wikipedia.org

Microsoft Office is an office suite of desktop applications, servers and services for the Microsoft Windows and OS X operating systems. wikipedia.org

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

Sales management is a business discipline which is focused on the practical application of sales techniques and the management of a firm's sales operations. wikipedia.org

A subset of the field of commerce, business development comprises a number of techniques and responsibilities which aim at: wikipedia.org

Management in business and organizations is the function that coordinates the efforts of people to accomplish goals and objectives using available resources efficiently and effectively. Management comprises planning, organizing, staffing, leading or directing, and controlling an organization or initiative to accomplish a goal. wikipedia.org

"A business plan is a formal statement of a set of business goals, the reasons why they are believed attainable, and the plan for reaching those goals. It may also contain background information about the organization or team attempting to reach those goals." wikipedia.org