The difference is dollar value and court. Petty larceny covers takings at or below the statutory threshold and is prosecuted as a misdemeanor in District Court, with a maximum of up to one year in jail. Grand larceny covers takings above the threshold (commonly understood to be $1,500 under RIGL § 11-41-5) and is prosecuted as a felony in Superior Court, with multi-year state-prison exposure and permanent felony-record consequences. Value is an element the state must prove, and a good Rhode Island larceny lawyer will challenge inflated valuations to keep a case in District Court whenever possible. Always confirm the present dollar figure with your lawyer, because the statute is periodically updated.