The Favicon is the small 16 pixel by 16 pixel pictures you see beside some URLs in your browser’s address bar. You can create a Favicon version of your logo and upload it if you wish.
You can use an online Favicon generator like this one to create your Favicon.
Then upload your Favicon to the Media library and copy the url.
To upload your Favicon go the WordPress Dashboard >> Thrive Themes >> Thrive Options >> General Settings and in there you will see the upload button where you can add your own Favicon.