Velocity in agile development measures the quantity of work a team can accomplish in a sprint. It can be measured in story points, hours or days. The higher the velocity of a team, the more features it delivers, the more value it brings to customers. Sprint velocity is a good measure in sprint project management to evaluate and estimate team productivity.
The measure of the velocity is based on multiple factors: the continuous integration (CI) process, the time to qualify the code changes, to test the regression, the security, the delivery, etc…