One thing that this article talks about, but could be more explicit about, is the different kinds of clown.

There's the kind we all think of -- white face, red nose, at the circus.

But there's other kinds too. I know the most about two related forms: commedia dell'arte and bouffon.

In commedia dell'arte, performers play different "stock characters" based on Italian society in the 1600s, when commedia was originally developed. Commedia is concerned with status within a society: rich/poor, servant/master, young/old. Each character has its own specific mask. One character might be the blue-collar working person, who isn't learned, but is not dumb. Another character is the rich person who thinks themself smart and cultured, but is neither. These performances are often partially scripted, partially improvised. One example is: https://www.youtube.com/watch?v=3DjGoDEks7U

In bouffon (mentioned in the article as the group Mil Grus). These characters are grotesque (physically -- often these performers put foam inside their clothing to make the character look inhuman) and outcasts. You might think of them as a tribe of people thrown out of society in the middle ages, who the king invites back in once a year. Because of their outcast status, they are allowed to say things that people inside that society cannot. One modern example is Red Bastard (who I've studied with), who can be seen here: https://www.youtube.com/watch?v=kFJWnfNUXnc.