The one above the meta description ?
This is the meta title for the page - in practical terms, it’s what will be displayed in the top bar of the browser. Choosing the title wisely will help with search engine placement
Not to be confused with filename - the file name is what will appear in the address bar, and will be a long string of php code unless you enable the SEO module, which dynamically changes the page’s filename to match your item’s name - this, combined with a well chosen meta title will massively help in search engine placement.
What bpaulette mentioned is a must if you want to have an overall good rank for your page. Google’s algorithm has changed a lot over the years, but one thing I doubt will ever change is the importance they give to the Title meta tag of you page. Make sure it’s always unique for every page and its title is relevant to the content of your page!
My 2 cents