These messages, called events, are interpreted by the program, and allow the program to respond to the user selecting a menu item, clicking on a button, and so on.

这些消息(称为事件)由程序进行解释，并允许程序对用户选择菜单项、单击按钮等操作作出反应。

youdao

But Annan visited Tehran this weekend, and Iran's nuclear program is most certainly a prime item on his agenda.

NPR: The U.N., the U.S. and the Middle East