How to use Vlookup in Excel?

I needed help using the vlookup function in excel. I have two sheets of data. One sheet w/ about 50,000 entries and the other with 20,000. The data on the sheet w/ 10,000 entries matches half the data on the other sheet. I need to somehow make a new list with just the matching data. Does anyone know how i can go about doing this? I was told that using a Vlookup would be my best option, but I’m not to certain how I’d go about doing that. Any help would be greatly appreciated!!

Thank you!