Favicon is the little icon which appears in the tab of your browser when you visit a website.
When people save your website URL as favourite, then this symbol will be displayed in the favourite in their browser, tablet or mobile device.
If you do not have a FAVICON then just google “create a favicon” and you would see lots of sites offering online creation tools.
Go to your WordPress and click on Plugins
Click on Add New
Search for plugins Type in favicon.
I chose one called Captain Favicon.
There should be a button which suggest to upload the favicon. Upload the favicon which you created in step 1.
Upload and save.
Now you should be able to see your favicon when you browse your website.
Here is a short video showing the steps.