Excel offers a large number of user interface tweaks, however the essence of UI remains the same as in the original spreadsheet, VisiCalc: the cells are organized in rows and columns, and contain data or formulas with relative or absolute references to other cells.

Excel was the first spreadsheet that allowed the user to define the appearance of spreadsheets (fonts, character attributes and cell appearance). It also introduced intelligent cell recomputation, where only cells dependent on the cell being modified are updated, while previously spreadsheets recomputed everything all the time or waited for a specific user command. Excel has extensive graphing capabilities.

When first bundled into Microsoft Office in 1993, Microsoft Word and Microsoft PowerPoint had their GUIs redesigned for consistency with Excel, the killer app on the PC at the time.

Since 1993 Excel includes support for Visual Basic for Applications (VBA) as a scripting language. VBA is a powerful tool that makes Excel a complete programming environment. VBA and macro recording allow automating routines that otherwise take several manual steps. VBA allows creating forms to handle user input. Automation functionality of VBA exposed Excel as a target for macro viruses.
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