Is light the same as electromagnetic radiation?

Yes, it is. Electromagnetic (EM) waves have frequency and amplitude (as well as polarity and a couple of other things), and because it has frequency, it can be distributed across a range of frequencies, or a spectrum - an electromagnetic spectrum. Light is a range of frequencies in what we call the optical or visible range. It is bounded on the lower end (lower frequency, lower energy, longer wavelength) by infrared (IR) light, and on the upper end (higher frequency, higher energy, shorter wavelength) by ultraviolet (UV) light.
Yes. Light is also called a "electromagnetic wave"