Favicon
In plain terms
The small icon representing a site in tabs and bookmarks.
Going deeper
A favicon is the tiny branding image browsers show in the tab, bookmark, and history for a site. It's a small but recognizable identity cue.
Under the hood
Served via link tags or convention; multiple sizes/formats support different devices and PWA icons.
Examples
Tab icons, bookmark icons, PWA home-screen icons, brand recognition.
Think of it like...
Like a tiny logo flag planted on your browser tab.