An eclipsing binary is a binary star system where one star passes in front of the other, detected by seeing the change in light when that happens, much as a transiting planet is detected. In effect, it is a type of variable star, E commonly used as the variable type.
It is one of a number binary-star classes based upon how the star is determined to be binary. Others:
A double-line detached eclipsing binary (DDEB) is an eclipsing binary, a double-line spectroscopic binary and a detached binary (not touching).