The second section visualizes your sales of the last year, divided in 12 months in a bar chart.
It shows the following key values on the left side. The Chart on the right side shows you the count of transactions that belong to your account.
The third section with a quick overview over your last transactions
The third section of the dashboard is a quick overview over your last transactions.
If you need a more detailed overview that shows more than just the last few sales, please check out the Transactions tab.