What Is Cportlet

I have read documentation, but I can’t understand what is CPortlet and what it is used for. I saw one of the usage is to create menu in column2.php

Could someone explain me, please.

CPorlet is just a way to modularize the display of information. If you look at the Blog demo, it has a number of CPortlets. One is used for ‘TAG’ display, pulling from the TAG table and adjusting size of the font depending on number of time it is used.