How to use lookup formula?

Hello there, could you please clarify what you mean by "lookup formula"? Are you referring to a specific function or method in Excel or another spreadsheet program, perhaps something like VLOOKUP or INDEX and MATCH? If so, could you elaborate on which one you're interested in and what specific aspect of its usage you'd like to know more about? For instance, are you looking for guidance on how to use these formulas to find and retrieve data from a table, or do you have a specific use case in mind that you'd like to discuss? Additionally, if you're working with a different type of software or programming language, let me know, as the approach to using lookup formulas can vary depending on the context.