Hornet or Wasps.

In my environmental science class we learned about the adaptation. I found the bugs resembling wasps or hornets which were next to my house. They were quite numerous, with around 10 members of their species. I don't know why they were all gathered there, but I assume they were trying to build a new hive or something. The next time I saw these bugs are in school. However, I went into the classroom, I couldn't find any wasps or hornets around there. If they were trying to build their new home, I assume that the school staff probably destroyed it or something.

I first wondered, whether they were hornets or wasps. Then I also wondered, if they were trying to build a hive, why did they choose that spot, where there is much human activity going on? Last, I wondered how did the staffs got rid of the wasps or hornets.
To find about more about hornets and wasps, I can use the Internet. In addition, they probably can tell me the distinction between those two. I could also use a library to find about some information.  Distinction between those two are that hornets' size are 1- 1.5 inches long and hornets' color are black and white; brownish-reddish. However, wasps' size are smaller than hornets, 1 inch or less, and the color of them are vary. 

https://www.orkin.com/stinging-pests/wasps/difference-wasps-hornets/