All a defensive zone does is take your space away, so move to another space.
Zone defence is a type of defence, used in team sports, which is the alternative to man-to-man defence; instead of each player guarding a corresponding player on the other team, each defensive player is given an area known as a "zone" to cover.
A zone defence can be used in virtually all sports where defensive players guard players on the other team.
In modern netball zone defence is not used that often, especially if the opposition have good passing skills.
See netball zone defence.