The Worksheet, in the word’s original impying, is a scrap of stationery on which one performs work. They come in many type shapes, most commonly linked with kid’s school activity assignments, tax forms, and accounting or another business environments. Application is increasingly expropriating the paper-based worksheet.
It could be a printed page that a child completes with a writing tool. No materials are required. It is “a single paper on which schedules activity, working time, specific instructions, etc. are recorded. A scrap of paper on which problems, ideas, or the like, are write down in temporary form.” In school, a worksheet may have questions for students and where to write answers.
In accounting, a worksheet is, or was, a piece of ruled paper with rows and columns on which an accountant could log information or perform calculations. These are often called columnar pads, also typically green-tinted.
In IT, spreadsheet application presents, on a PC monitor, a UI that like one or more paper accounting worksheets. Microsoft Excel, a favorite spreadsheet program, bases on a single spreadsheet (more technically, a 2 dimensional matrix or array) as a worksheet, and it bases on a group of worksheets as a workbook.