تعريف ومعنى "the world [is] {one's} oyster"

What is the origin of the idiom "the world is one's oyster" and when to use it?

The phrase is thought to have originated in the 17th century, when oysters were considered to be a special food and were often served as a symbol of wealth and prosperity. "The world is one's oyster" is an idiom that means that one has unlimited opportunities and possibilities. It is often used to encourage someone to be optimistic and to take advantage of all that life has to offer.