Microsoft Excel is an electronic spreadsheet program that is used to organize data into rows and columns to perform calculations and visually represent data in graphs. It has over 1 million rows and 16,000 columns. Each cell has a unique address defined by its column letter and row number, like A1 or D2. Excel allows users to reference cells within the same worksheet or across other worksheets and programs. It has various tabs for formatting, inserting objects, working with formulas and functions, analyzing and managing data, reviewing documents, and customizing the spreadsheet view. Excel is useful for tasks like budgeting, data analysis, and reporting, but can also be time-consuming to learn and use fully.