Most standard first-aid kits for the home and car have very little, if anything, to treat serious or major bleeding!
The majority of kits tend to have a handful of very thin and often small dressings, which can be used to cover up minor wounds, but are not very helpful in the case of a wound that is bleeding heavily.
A wound dressing consists of a thick pad (designed to hold blood and enable it to clot) that has been sewn into a long bandage. You simply place the pad on the wound and then quickly wrap the bandage around it. It makes it a great deal easier to treat severe bleeding quickly and effectively, as opposed to trying to hold a towel or similar to the wound and then bandage it in place.
Essential for every first-aid kit!