Complex sentence: When connected to a computer the base station will upload data to the Fitbit website, where a number of features are available: seeing an overview of physical activity, setting and tracking goals, keeping food and activity logs, and interacting with friends.
Split into simpler sentences: When connected to a computer the base station will upload data to the Fitbit. From the website, a number of features are possible: seeing an overview of physical activity, setting and tracking goals, keeping food and activity logs, and interacting with friends.