Are these the same things called differently or not?
The person who taught the ceramics class is a friend of my mother’s.
Every journalist has a novel in him, which is an excellent place for it.
There are now only two schools in the area that actually teach Latin.
Doctors use the testing kit for regular screening for lung and stomach cancers, which account for 70% of cancers treated in the western world.
What is the difference between these two types of clauses (restrictive and non-restrictive, and defining and non-defining)?