The molecular geometry is what we actually want to know about a molecule. Where are the atoms! The electronic geometry is an idea. The molecular geometry is something we can probe in the lab.
To get the molecular geometry, we simply have to take the electronic geometry and look at how many electron regions are bonding and how many are non-bonding.
If there are no lone pairs (non-bonding regions), then the molecular geometry and the electronic geometry are the same. If there are lone pairs, then we need to give the molecular geometry a new name based on where the atoms are located.
For example, for a tetrahedral geometry if there is one lone pair (like ammonia), then we call this geometry trigonal pyramidal because the atoms sit at the corners of a pyramid that has triangular sides. If the electronic geometry is tetrahedral and there are two lone pairs (like water), then the atoms are arranged in an angular or bent shape that we creatively call "angular" or "bent."