Microsoft Excel is a spreadsheet program used to store and retrieve numerical data in a grid format of rows and columns. Excel allows users to enter data, perform calculations, analyze data using formulas and functions, visualize data through charts and graphs, and conditional formatting. It is widely used in workplaces for tasks like tracking sales, expenses, budgets and more. Excel can also help users identify trends in data, combine data from multiple sources, and access files online through Microsoft Office 365.