Bookkeeper(记账员)：A bookkeeper refers to a person usually employed by a small to mid-size company or other organization to process and record the large  volume of transactions involving sales, purchases, payroll, collection of  accounts receivable, payment of bills, and more.

Single-entry System(单式记账）：The single-entry system or bookkeeping refers to a method of  bookkeeping that recognizes only one side of a business transaction and usually  consists only of a record of cash and personal accounts with  debtors   and creditors.

Big Data（大数据）：Big data refers to an accumulation of data  that is too large and complex for processing by traditional database management  tools.