An idiom is a phrase that has a figurative meaning quite apart from its literal meaning. "Roll up your sleeves" for instance means to get to work. If I took it literally, I would only understand it as someone adjusting the sleeves of his shirt. A phrase may be an idiom; however, it might also have a literal meaning. "Driving the car" has not other meaning (usually) other than driving a vehicle. Top sum up, an idiom is always a phrase; however, a phrase is not necessarily an idiom. Other idioms: Take shot a something = Give something a try Lay your cards on the table = Tell everything, don't hold back. Roll up the streets = Close everything down in a community.

An idiom is a phrase and its meaning cannot be determined by the literal definition of the phrase itself, but refers instead to a figurative meaning that is known only through common use - for example, the common expressions: "turn over a new leaf" and "fancy seeing you here." A phrase is a group of words that functions as a single unit in the syntax of a sentence. For example: the house at the end of the street.