Windows 8 introduced the "metered connections" feature. If you enable it, it can reduce the amount of data you send and receive via your limited data plan and help you save money or avoid bill shock. Some Internet service providers can charge by the amount of data used (the amount of data sent and received by your PC). The service provider monitors your Internet connection data use.
With programs and services in Windows communicating with the internet almost all the time today, this data limit can be reached quite easily. If you exceed the data limit you might have to pay extra amount or get your download speed reduced until the next month. If you have such a limited data plan, setting your network connection as 'metered' in Windows can help you reduce the amount of data you send and receive. Windows turns off unnecessary transfers while on a metered connection and tries to conserve bandwidth.
Now, in Windows 8.1, Microsoft has completely changed the UI for setting a connection as 'metered'.
