A conditioner is usually used after washing the hair to condition and nourish the hair. There are several reasons why it makes sense to use a conditioner:

1. Detangling: A conditioner helps detangle hair, making brushing and styling easier and reducing the risk of hair breakage.
2. Moisture: A conditioner can lock moisture into the hair, helping to prevent dryness and split ends.
3. Shine: A conditioner can help make hair look shinier and healthier.
4. Protection: A conditioner can protect hair from environmental damage by creating a protective layer around the hair.

In summary, conditioner can help keep hair looking healthy and nourished by moisturizing, detangling and protecting hair from environmental damage.