The snap package manager in ubuntu failed to work properly

Question

After I upgraded my Ubuntu from 16.04 to 18.04 it came to my attention that the nodejs was somehow moved to a folder /snap/bin/bin.

After some googling it seems that snap is some package manager that I've never heard of - a suggested way of using it is like:

snap install node --classic --channel 9/stable 
chown -R $USER:$(id -gn $USER) /home/jon/.config 

what's this snap thing? What's wrong with apt? I used to do this for installation:

apt-get install nodejs
apt-get install npm

I never had problems, now even though I managed to get npm to work, it start becoming annoying, for example: when I tested some vuejs project, I need to append "--scripts-prepend-node-path" to the command:

npm run dev

and for some other vuejs projects such as the demo project of quasar, "quasar play", it simply not working after issuing this command:

quasar dev

error message:

npm ERR! missing script: dev

The same command worked in my iMac machine though.