XLS is a file format used by Microsoft Excel for storing spreadsheet data. It supports a wide range of functions, including calculations, graphs, and formulas. XLS files are commonly used in business, finance, and data analysis. However, it has been replaced by XLSX in newer versions of Excel for better compatibility and file size.
CSV is a text-based file format used for storing tabular data, where each value is separated by a comma. It is commonly used for importing and exporting data between applications such as spreadsheets and databases. CSV files are simple and lightweight, making them easy to process and manipulate.