To all Catia Electrical Designers

I have a question that has bugged me my whole career of over 18 years as a Harness design Engineer in Automotive.

I have never used the command in Catia V5 or 3DEXPERIENCE Electrical Part Design called "define shell" and "define shell connection point"

I worked in mass production automotive design and Formula One for many years and never encountered a part that needed to be designed as a shell.

Now I am a Team Leader and some freshers in my team asked me what can be defined as a shell in reality and didn't know what answer to give them.

So I wanted to ask, can anyone give a few examples of what a shell is or can be in reality?

Cheers!

Edu 3DEXPERIENCE CATIA