A Shared Data Plan allows multiple devices, such as smartphones and tablets, to use a single pool of data. Instead of each device having its own separate data plan, users can share a set amount of data among all their devices. This can be more cost-effective for families or groups, as it often reduces the overall monthly bill. These plans are typically offered by major mobile carriers like Verizon, AT&T, and T-Mobile. Users can monitor their data usage through apps provided by the carriers, ensuring that they stay within the shared limit and avoid overage charges.