Mobile or Cellular Data Plans
A mobile data plan from your cell phone provider, for example, allows you to access the 3G or 4G data network to send and receive emails, surf the Internet, use IM, and so on from your mobile device. Mobile broadband devices such as mobile hotspots and USB mobile broadband modems also require a data plan from your wireless provider.
Wi-Fi Data Plans
There are also wi-fi data plans especially useful for travelers, such as the services offered by Boingo and other wi-fi service providers. These data plans enable you to connect to wi-fi hotspots for Internet access.
Unlimited vs. Tiered Data Plans
Unlimited data plans for cell phones (including smartphones) have been the norm most recently, sometimes folded in with other wireless services in a one-price subscription plan for voice, data, and texting.
AT&T introduced tiered data pricing in June of 2010, setting a precedent for other providers to eliminate unlimited data access on cell phones. Tiered data plans charge different rates based on how much data you use each month. The benefit here is that these metered plans discourage heavy data usage that could slow down a cellular network. The downside is that users have to be vigilant about how much data they're using, and for heavy users, tiered data plans are more expensive.
Mobile broadband plans for data access on laptops and tablets or via mobile hotspots are typically tiered.