Here is a simple way to remember the difference between conventional motor oil and synthetic motor oil
(disclaimer: in no way does this explanation have any kind of scientific terminology except for the words molecules and dinosaurs).
 
Conventional Motor Oil comes from dinosaurs   |   Synthetic Motor Oil comes from laboratories
 
Imagine the molecules that make up regular conventional oil look something like this:
 
.  .  . 
. .   .     .
.        .                   Note that these molecules are all jumbled and move in all different directions
.    .    .        .
.   .         .
 
 
Now, imagine the molecules that make up synthetic motor oil look something like this:
 
...............
..............
..............              Note that these molecules are all organized and work together to move in unison.
..............
...............

 
 
This is the benefit of synthetic oil; it has been scientifically modified to perform in a certain manner.  Whereas, conventional oil has simply been dug up from the ground, cleaned and refined with various additives.
 
Something to ponder....hope this helps answer your car questions