The "HOLD MODE" - How does it work?

Hello, I'm a new owner of a 2007 Chevy Aveo Hatchback LT, it features an automatic transmission. I'm wondering about the HOLD function on the shift console. The operator's manual says the following:

(Using HOLD to)MANUALLY CONTROLLING SHIFT
"Select HOLD MODE to use your automatic transaxle like a three-speed manual transaxle." - page 115.

What exactly is the "HOLD MODE" all about? How do I use it properly?

Thanks

Well, after some searches through the site here, I guess it's mostly for wet+snowy road conditions, keeping the car in a low gear without shifting into a higher one and causing slippage...