Does your skin look dull & feel tight?
Dry Skin ~ is a type, lacks oil, increase sensitivity, lack of protective oils, feels dry all over.
Dehydrated Skin ~ is a condition, lacks water, can be flaky, taunt, dry & itchy, forms fine lines easily, environmental factors can be the cause.
Dehydration is a lack of water, not oils, so even oily skin types can be dehydrated.
The purpose of hydrating is to bind water to your skin and moisturizing is to prevent water from leaving your skin, it’s important that hydration comes before moisturizing (when applying products topically).