Sleep studies were the gold standard for tracking your sleep habits in the past. These involved you being hooked up to over 20 wires and sleeping in a sleep lab with a person watching over you at night as your sleep. This technique is called polysomnography and the cables and sensors are fine-tuned to track eye movements, leg movements breathing and heart rate. This type of study changes your environment and may actually change the manner in which you sleep at home in your own bed.
Sleep trackers allow you to monitor your sleep through an accelerometer and only one sensor to track movements while you sleep. This is a much simpler device that you can use to determine sleep patterns and make changes in your daily life to gain more restful and longer sleep.