What is delta velocity?

Delta velocity, also known as delta v or Δv, is the change in velocity of an object over a given time period. It is a vector quantity, meaning it has both magnitude and direction. Delta v can be calculated by subtracting the object's final velocity from its initial velocity. It is an important concept in aerospace engineering and space travel, as it is used to determine the amount of propellant needed to achieve a certain change in velocity (such as entering orbit or leaving Earth's atmosphere). The larger the delta v required, the more fuel and energy is needed to achieve it.