The term gift card does not have a legal definition. The term is normally used synonymously with the term voucher card.
A gift card is a prepaid payment product that can be used to pay for goods and services at one or more merchants who accept this gift card. As a general rule, the gift card is assigned an electronically stored value.
A gift card can be e-money. However, there are also many gift cards that are not e-money. Therefore, the term gift card does not provide any indication as to whether or not the issuer requires a licence.