What's A favicon
A favicon is a small image (icon) representing your website - favicon is short for favorite icon. Favicons are the tiny images that show on the tabs of your web browser and bookmarks.
Favicons should be easily and quickly identifiable with your website. They should match the logo or some other unique characteristic of your website. In case of real estate websites, you could use the picture of the agent.
Why Have A favicon
They are important for branding and usability.
They help users find a website quickly within a long list of bookmarks, and help reassure the user that they are in the right website.
Furthermore, it looks like the website is not being neglected.
How To Create a favicon
The easiest way to create a favicon is to use an online generator. Here are a few examples: https://www.favikon.com; http://www.favicomatic.com; https://www.favicon-generator.org.
What File Type To Use
You can use ICO, PNG, GIF, or JPG
ICO is preferred because it's supported by all browsers and it can embed several sizes within it, for example, favicomatic.com creates an ICO file with 16x16 and 32x32 images.
At a minimum you should have a 16x16 or 32x32 favicon, but you could also have other larger sizes for mobile IOS and Android. It's up to you. I find it enough to just have the 16x16.
How To Add The favicon To Your Website
It depends on your website CMS (content management system).
Instructions for the most used CMSs:
If your CMS is not listed above, simply do a Google/Bing search to find out how to do it for your CMS. For example, if you use Wordpress, type in "how to add favicon to wordpress"
If you don't use a CMS, simply FTP the image file into the root of the site or the images folder.
Once the favicon is uploaded, you need to add the following code to all the pages of the website between the HEAD tags. This is easily done if you use includes for the common areas of your website: header, footer, sidebar, etc.
That's it. It's pretty easy.