Gelled vs Ungelled Soap - What's the Difference?

Have you ever heard of gelled or ungelled soap?  I really never had heard of either until I came across this posting from Bath Alchemy.  In a recent post called Gelled vs Ungelled Soap - What's the Difference? , Bath Alchemy had said that they had a lot of questions on what was the difference between the two and there seems a lot of confusion on this subject.  This posting intrigued me and I hope you will read this like I am going to because I am interested in learning more about this.