With the multi-site option, you can host multiple websites on a single web hosting plan.
You can divide your disk space between your different websites as you see fit.
What's more, you don't need to manage several hosting packages, with different access codes and expiry dates.
Advantages for your visitors
Put your different websites online.
Create the directories that the domain names will point to.
Your visitors will visit the websites without knowing that they are sharing the same web hosting plan.