Why is electromagnetic radiation important?

Electromagnetic Radiation is important in Astronomy because it helps us see the universe. It helps us see on earth to (Visible Light) lol. For example, X-Rays are released by Pulsars, but not visible light, so that's how we know they exist. Here's a list of why each type is important (other than the previous reason):

Radio: Communication, WiFi. Radio astronomy helps us observe stars, galaxies, radio galaxies, quasars, the cosmic backround, pulsars, and masers.

Microwave: Microwaves use this - lol. Let's us observe "galaxy formation & evolution, stellar & planetary system birth, the composition of solar system body atmospheres, in addition to the CMB." - Universetoday.com

Infrared: With equipment we can see in the dark & through walls, as well as detecting the heat of an object. Let's us see things on the upper end of the visible section.

Visible: How we see our world, gives us those stunning images of the universe (From the Hubble space telescope specifically).

Ultraviolet (UV): Triggers Vitamin D production, helps disinfect. Helps us observe "chemical composition, densities, and temperatures of the interstellar medium, and the temperature and composition of hot young stars. UV observations can also provide essential information about the evolution of galaxies."- Wikipedia.com (sorry)!

X-Rays-Pretty obvious ( I'm going to get a X-ray), Pulsars, Quasars emit these.

Gamma Ray: The weird one; observed in the extremes of the universe: GRB's (Gamma Ray Bursters - Super Nova Process), and atomic bombs.