Facebook categorize users in networks. Network could be your city, country, company or university. It makes easy for Facebook to show relevant data based on the users networks. Facebook was launched with Networks filter which made it different from other social networks but last year when Facebook did the redesign of Facebook, it ditched Networks filter on homepage. Users were still able to join a network but there was no way to filter out user by a given network like it was before.
Now Facebook has restored this old functionality. You can see a list of top 5 networks of your friends. This time Facebook doesn’t consider city or country as a network. It shows only schools, colleges, universities and companies as networks. You can see the list of ‘Networks with your friends’ on your Facebook profile page under the friend section.
how can the info facebook posts on this section be changed or added to, I have friends in university network and it is not noted?
Go to Settings-> Account Settings-> Network there you can add new networks.