fontawesome.com is the next generation of the web’s favorite icon library.
for example, one can easily use CSS to get it downloaded on your website for example Facebook square
Open link https://fontawesome.com/v5.15/icons/facebook-f
Use below once line code in HTML page to view Facebook icon.
<i class="fab fa-facebook-square"></i> <br> <<i class="fab fa-facebook-f"></i>
Facebook Font will look like as below.
Fontawsome site contains many free icons here is the link https://fontawesome.com/v5.15/icons?d=gallery&p=2&m=free
This site contains many icons of different sizes. SVG files are also available.
Sizes are available for each icon.