The word essential means most important. It refers to something or someone that you cannot do without.
Sheila is essential to our work. Without her research we would not be able to draw conclusions for our paper.
The essential ingredient in my lasagna is a special ricotta cheese I get at an Italian market in Philadelphia. It would not be the same great dish without it.
Essential can also mean natural. In this case, it implies that something or someone contains the essence of a thing, such as a plant. Essential can also refer to food, water, or any other life sustaining material.
I use a shampoo containing essential oils. It contains a combination of natural oils and fats that nourish your hair.
Have you tried Herbal Essentials? It is the new, natural body wash that contains ground up herbs that will refresh your skin.
Vital is used to describe something or someone as the most important or necessary to the life of. In this case, vital refers to something as life giving.
Getting married was a vital decision. My life would not have been the same if I'd not met John and built a life with him.
Vital can also mean energetic and lively. It is used to describe someone or something that has a forceful personality. The word vitality is used to describe mental or physical strength and vigor.
Our boss is a vital leader. I have never met someone with so much energy and passion for their job.
The loss of such a vital soldier was tragic. He put everything he had into fighting for his country and protecting people.