Joules are defined as a unit of energy measurement, but there are several synonyms that can also be used in place of this term. For example, energy can sometimes be referred to as power, work, or force. Other synonyms include watts, calories, and BTUs, which are all commonly used in physics and engineering. Joules can also be expressed as kilojoules, megajoules, or gigajoules, depending on the specific quantity being measured. Alternative terms for joules are often used in different contexts and industries, but all ultimately refer to the same fundamental unit of energy.