Analytics refers to all the data you have collected with your Tracker, since you began tracking. You can access your Analytics on the Trackers page by scrolling to the Tracker, and then by clicking either "Twitter" or "Instagram" links at the bottom of the box. This will default to an Analytics view that includes up to the last 7 days of data. You can then adjust the date to look at any time period that you were tracking. If you want to save those Analytics as a report that can be accessed in the future via URL or export, click again in the upper right hand corner to "save as a report."
You can learn more about Analytics and Reports by watching this video: