Puzzle Elements/Energy Balls

The energy balls, or formally Aperture Science High Energy Pellets, are one of the essential Portal concepts. They are introduced in Test Chamber 06.

The puzzle the energy ball creates comprises of putting the ball (launched by a specific launcher) into the catcher which activates mechanisms such as doors, scaffolds and incinerators.

When the player touches the energy ball, she's killed instantly. This is known (as GLaDOS said) as "vaporization".