A sommelier, or wine steward, is a trained and knowledgeable wine professional, normally working in fine restaurants, who specializes in all aspects of wine service as well as wine and food pairing. The role in fine dining today is much more specialized and informed than that of a wine waiter. It is opined by Sommeliers Australia that the role is strategically on a par with that of the chef de cuisine.

Though 'sommelier' is a job title potentially anyone may claim. However, becoming a professional certified sommelier often requires some combination of experience and training. Formal education (a bachelor's degree is not required, but individuals may do a two-year associate degree), is necessary. One can become a sommelier only through experience in the restaurant or wine industry as a qualification, though many choose to become certified or educated by one of the many certifying bodies. The certification is offered by a wide range of educators: though a basic education may be attained for US$800–$3,750 over the course of six months, advanced professional certification requires years of costly study, practice and experience.

In modern times, a sommelier's role may be considered broader than working only with wines, and may encompass all aspects of the restaurant's service, with an enhanced focus on wines, beers, spirits, soft-drinks, cocktails, mineral waters, and tobaccos.

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