What formula should I use?

Hello!

I work in HR and was trying to see if I could find a formula that will do what I’m looking for. 

In one tab of my spreadsheet, I type in all the names of applicants that apply through Indeed. In another tab, I type in all the names of applicants that apply through our website. I want to add a column to the Indeed list next to the names that will put an X if their name appears in the list of applicants from our website and leave it blank if they are not in the list. 

It seems like it would be a simple formula but I’m not sure where to start.

Thanks!