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What is "first contact", "second contact", "third contact", and "forth contact" ?

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When a total eclipse or annular eclipse occurs, observers can see four phases on the ground. When the moon's disk first touches the sun's disk, it is called "first contact". After that, partial eclipse starts, and magnitude of eclipse increases as time passes. Next, the moon's disk completely covers the sun's disk in case of a total eclipse, this moument is called "second contact". In case of an annular eclipse, "second contact" is the moument that the moon's disk is completely included by the sun's disk. After a few minutes or seconds, total eclipse ends, and the moon's disk begins to uncover the sun's disk in case of a total eclipse. This moment is called "third contact". In case of an annular eclipse, it is the moment that the moon's disk finishes to be included by the sun's disk. After that, magnitude of eclipse is decreases, and finally the moon's disk does not touch sun's disk. This moment is called "fourth contact".