The Closed Change is known as the Box Step in some other dances.
Changes also may be Right and Left, making four types of changes in total: Right Closed, Left Closed, Right Open and Left Open.
In Right changes the man starts from the right foot, while in Left ones the man starts from the left foot.
A change is called "closed", if on the last step the moving foot closes to the standing foot. A change is "open", if on the last step the moving foot passes the standing foot.
All four changes are similar, therefore a detailed description is only for the Right Closed Change.
The man steps forward on right foot while the lady steps backward on the opposing (i.e., left) foot. They will then step to the side (and possibly slightly forward, in relation to the man) on the other foot, and conclude the figure by closing the first foot beside the second. Each step takes up a full beat of the music.
Details of International Style Waltz technique: