Definition of "Transition" :
noun: the act of passing from one state or place to the next
noun: a passage that connects a topic to one that follows
noun: a musical passage moving from one key to another
noun: a change from one place or state or subject or stage to another
noun: an event that results in a transformation
verb: make or undergo a transition (from one state or system to another)
"The airline transitioned to more fuel-efficient jets."
verb: cause to convert or undergo a transition
"The company had to transition the old practices to modern technology."