Web fonts are hosted by an external server or service such as Google Web Fonts, Adobe Typekit, or Monotype Inc. Fonts.com. These web fonts allow designers to pull typefaces from a server to display those typefaces on their own webistes.
WIthout Web Fonts, a users xomputer may not display the right font becuase their computer lacks the proper files. IT is very improtant to declare and use web fonts, or a users computer will determine a replacement automatically. Sometimes those replacements are embarrassing.
Web Fonts vs @font-face
@font-face is a css feature that allows you to use fonts that exist on your computer as a web font. It is advisible that you oby use @font-face when you are certain your typeface has the correct copyrights that allow it to be used as a web font.
Web Fonts are typefaces that have been optimized and cleared for use on wesites.
Pseudo classes deal with events in css. Typically, a pseudo clas ill wait for the user tp perform a certain action before it runs the css code.
Pseudo classees are written with selectors, like this...
In the example above, the pseudo class is :hover. This class waits for the user to hover their mouse cursor over an element before the CSS will run.