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

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

Accounts receivable also known as Debtors, is money owed to a business by its clients (customers) and shown on its Balance Sheet as an asset. wikipedia.org

Bookkeeping is the recording of financial transactions. Transactions include sales, purchases, income, receipts and payments by an individual or organization. Bookkeeping is usually performed by a bookkeeper. wikipedia.org

Accounts payable is a file or account sub-ledger that records amounts that a person or company owes to suppliers, but has not paid yet (a form of debt), sometimes referred as trade payables. wikipedia.org

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

Xero is an online accounting software product for small and medium-sized businesses, as well as for personal finance. The product is sold by subscription (a distribution model commonly known as Software as a Service or SaaS) requiring the payment of a monthly fee. wikipedia.org