What is the difference between a lunar eclipse and the moon phases?

Answer 1

Eclipses involve a shadow from one object to another. Moon phases involve the moons own shadow on itself because part of the moon may be in the shade so we can't see it. During a full moon we see all of the moon lit up by the sun.

Answer 2

The lunar phases describe how much of the lit surface, the "day side" of the moon, is visible from Earth based on its angle relative to Earth and the sun.

A lunar eclipse occurs when the moon passes through Earth's shadow and always, therefore, occurs during a full moon.