The term container also refers to any class that holds or organises other objects such as trees, bags and Vectors. Though Java folk usually call those collections to avoid confusion.

A Component can belong to at most one Container at a time. To move a Component between Containers, you must first remove it from the old one then add it to the new one. Similarly you may add a Component to a Container only once, unless you remove it first. You can simulate the effect of a Component moving between Containers by having two Components and keeping only one visible at a time.

Swing uses the same AWT Container class.

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