Question

why do we use linking cell​

Answer 1

Cell linking is useful when you want to consolidate information from multiple sheets. Use cell linking to create a master or roll-up sheet, to keep track of cross-project date dependencies, or simply to ensure that values stay current across a collection of sheets without a lot of re-typing....

Answer 2

Spreadsheet also allows you to link the cells from various worksheets and from various spreadsheets to summarise data from several sources.