extragalactic background light

The term extragalactic background light (EBL) typically refers to cosmic background radiation (CBR) over a range of wavelengths including visible light (the cosmic optical background) and more on each end: typically on the order of 0.1 to 1000 μm, spanning a range from the cosmic microwave background (CMB) into ultraviolet. Generally the term is intended to exclude the CMB, i.e., to mean "all that other electromagnetic radiation (EMR) around the universe". EBL is challenging to measure because of galactic sources of flux. Other terms used for various diffuse light:

• DEBRA for diffuse extragalactic background radiation - roughly the same as EBL or CBR, though whether it includes the CMB probably depends on the writer.
• DGL for diffuse galactic light - for EMR from galactic sources, e.g., the response of the interstellar medium (ISM) to EMR from all sources, most of which would be from stars.