What is the difference between installing a package using pip vs. apt-get?

Question

I\'m trying to deploy a Django site on an Ubuntu machine. I need to install Psycopg2 and PIL but it seems that I\'m able to install them using either apt-get or using pip. Is th

Answer 1

I found something about this. My ubuntu has both python version 3.6 and 3.7. When apt install python3-xxx, xxx will be installed at /usr/lib/python3/dist-packages, but pip3 install xxx at /usr/local/lib/python3.7(my default python version)/dist-packages. And when change python to version 3.6, xxx installed by pip3 could not work, while installed by apt works fine.