The question is a little ambiguous, but I'm guessing that the most likely answer is "strain relief".
An air jacket is a jacket with airtight cells, used to assist someone in keeping buoyant while swimming.
The outer jacket act as an insulator.
water jacket saves us from the force of the water we are in.
If you place a thermometer by a person skin in a winter jacket it would be warm because the jacket is keeping in the heat.
The outer jacket on a fractionating column is used to insulate against heat loss from the inner jacket during distillation.
A flak jacket is a protective garment designed to worn over the torso, keeping the delicate internal organs and ribcage safe from harm on the battlefield.
Traditionally, a parka jacket would reach knee-length. These are sometimes referred to as anorak's and the garment was invented by the Caribou Inuits as a method of keeping warm.
To keep you from getting shocked and resist electrical leakage
A bullet proof jacket is made from several thin layers of a material known as kevlar ( Kevlar is a registered trade mark). Kevlar is a para-aramid synthetic fibre. Some vests also allow for metal plates to be inserted. While kevlar is light-weight, inserted metal plates make the vest heavier. Though if the vest stops a bullet, I doubt the wearer would mind how heavy the vest was.
they carry small pouch just because ladies jacket is already present .........which work for carrying biger items.........
Thick animal furs, such as fox, wool, and coyote, are good to line the inside of a cold weather jacket. The purpose of these furs is to keep the wearer warm.
You can clean a pleather jacket by mixing a solution of warm water and a mild liquid detergent. Gently wipe the jacket with a non-abrasive sponge. You can spray an alcohol-based all-purpose cleaner to remove any tough stains, then rinse using warm water and a clean sponge. Use a lint-free towel to dry the jacket.