Moisturizers for hair are the daily products that will be the most hydrating.
If your hair is very dry and / or very porous, you will need a fairly thick cream that will help lock in the moisture in your hair fiber.
Creams are the cosmetics that will be the thickest. These hair products are indeed very rich in butter and oil (but always with a hydrating water base).
These moisturizers can contain shea butter, castor oil to optimize the sealing of your cuticles. To these emolient ingredients can be added humectants such as glycerin or aloe vera which allow your hair to build up a reserve of hydration.