Windows 8 includes data usage tracking features, useful if you connect to networks that have data caps, like 3G or 4G connections. You can see the estimated data usage info for any network you’ve connected to by right-clicking (or touching and holding) the desired network and selecting Show estimated data usage.
Viewing the estimated data usage of a network.
You can also set networks as a metered connection, which will then disable Windows Update from downloading updates (except for critical security patches) and possibly disable or reduce data usage from other Microsoft and non-Microsoft Applications as well. To set a network as metered, right-click (or touch and hold) the desired network and select Set as metered connection.