Diff between Assigning CAL and giving section access??

[#1]

What is the difference between assigning user a CAL and giving section access??

Both are for getting access and viewing data. Then is it sufficient if we use only section access instead of buying more CALs?

Can someone explain this point.

[#2]

A user must have a licence to view a document.

Section access is something completely different. It's a way of reducing/restricting data based on the user.

[#3]

Thank you