Worksheet, in the word’s original impying, is a piece of stationery on which one performs activity. They come in several kind forms, most ussually linked with kid’s school work assignments, tax forms, or accounting or other business sphere. Application is increasingly expropriating the paper-based worksheet.
It can be a published page that a kid finishes with a writing instrument. No other materials are required. It is “a sheet of paper on which work schedules, working time, special guidances, etc. are recorded. A piece of paper on which problems, ideas, or the like, are set down in tentative form.” In education, a worksheet may have questions for students and places to write answers.
In accounting, a worksheet is, or was, a scrap of regulated paper with rows or columns on which an accountant could record information or perform calculations. These are oftentimes named columnar pads, and exclusively green-tinted.
In IT, spreadsheet software presents, on a PC monitor, a UI that such one or more paper accounting worksheets. MS Excel, a favorite spreadsheet program, refers to a single spreadsheet (more technically, a 2 dimensional matrix or array) as a worksheet, also it bases on a collection of worksheets as a workbook.