Gratuity is a sum of money given to service workers, such as waitstaff or taxi drivers, as a token of appreciation for their service. It is typically calculated as a percentage of the total bill, often ranging from 15% to 20%. Gratuity is not mandatory, but it is a common practice in many cultures to reward good service. In some countries, gratuity may be included in the bill as a service charge, while in others, it is left to the discretion of the customer. Understanding local customs regarding tipping can help ensure that service workers are fairly compensated for their efforts.