What is fresnel operation?

Hello all.

Question is in the title. I am new to graphics rendering and there are a lot of terminology. Can someone please explain what fresnel is?

I see fresnel in unreal engine when people deal with translucent objects such as glasses. What is it in the fresnel that everybody uses it for translucent object. When I googled the term I only find technical documentations that only some people can understand.

Could you guys can explain as you would explain to little child? So other new people, too, can understand?

Thanks in advance.

This should get you started

To add onto what Death posted aboveā€¦ Check this out for a lot of terms regarding rendering. Good luck.

http://wiki.polycount.com/wiki/Category:Glossary