A data plan is a service provided by mobile phone carriers that allows users to access and use the internet on their devices. The term refers specifically to the amount of data that a user has purchased or subscribed to, which determines how much they can stream, download, and browse online without incurring additional charges. Data plans typically come with a certain amount of high-speed data allowance per month, after which the speed may be reduced or the service may be temporarily suspended until the next billing cycle. The cost and specifications of these plans can vary depending on the carrier and the user's needs.