What is Sprint?
Sprint is certain period of time in which a specific work can be completed. Usually sprint length can be decided by the team and suggested by scrum master. The team consists of developers, testers, DBAs, managers. They discuss and decide how much time they need for finishing specific amount of work. This duration is called sprint. Usually a sprint length lasts anywhere between 2 to 4 weeks.
What is velocity of a sprint?
Sprint Velocity can be defined as the amount of work done by a team during sprint. It can be measured in number of units of work done during a sprint interval.