Spreadsheets display data and formulas in a table form (lines and columns) called a worksheet.
A worksheet is made of lines (numbered with numbers) and of columns (numbered with letters). The intersection of a line and a column is called a cell. A cell is therefore represented by a number and a letter.
A worksheet can contain up to 65,536 lines and 256 columns, more that 17 million cells.
Each of the cells on a worksheet may contain values. These values are entered directly (numbers, text, date, etc.) or are automatically calculated by the spreadsheet. This is referred to as formulas, meaning expressions that calculate a value in function of one or more values in other cells on the worksheet.
Spreadsheets have a large number of integrated functions for math calculations, statistics, etc.
Here is an example of a worksheet that contains student's grades for which the spreadsheet automatically calculates the averages: