A metaphor is a figurative language device that represents one thing as if it were another, or compares two things not normally viewed as similar, such as time is a thief. This comparison draws attention to the way time is quick and stealthy. Simile
Velocity is the rate of motion, speed or action. An example of velocity is a car driving at 75 miles per hour. velocity. pl. velocity. pl. Rapidity or speed of motion; swiftness. Physics A vector quantity whose magnitude is a body's speed and whose direction is the body's direction of motion.
(in agile software development) Velocity is a term used in agile software development to illustrate the rate of progress for a team or a set of teams (i.e. a project/program). The simplest way to define velocity is: the number or user stories a team/project can do in one sprint (do here means that it really is done and potentially ready to ship).