Conjunction or birth of new moon is the same thing. “A conjunction occurs when the Moon passes between the Earth and the Sun; but because the Moon usually passes north or south of the Earth-Sun line, it specifically occurs when the Earth-Sun-Moon plane is perpendicular to the plane of Earth’s orbit around the sun.” This moment is called “New Moon Birth” or conjunction. At this moment the sunlight falling on the moon cannot come to the earth. In other words new moon is “No Moon”. No one can see this “New Moon” even by most powerful telescopes.
(Courtesy of Moonsighting.com)