Your team's velocity is the amount of work the team has shown it has completed in an iteration. You can use this information to help estimate how much work can be completed in future iterations.
Velocity only makes sense as a relative measure. There is no specific velocity that is good or bad or standard, because no two teams take on work of exactly the same scale or complexity. However, if your team's velocity is increasing from sprint to sprint, you can surmise that you are on the right track.
Average velocity
The average velocity is calculated for completed and ongoing iterations and is displayed only on the Release planning folder summary page. Average Velocity calculation is as follows:
Average velocity = Sum of iteration velocity of all iterations within the specific Release/Total number of iterations
In the above calculation, Iteration 1.1 (being the subfolder) is not included. Similarly, velocity calculation for Iteration 1 does not take into account its subfolder Iteration 1.1.