Light IS electromagnetic waves.
"Light" is any electromagnetic wave that you KNOW about when it gets into your eye. There are a lot of other electromagnetic waves that you DON't know about even if they get into your eye, because they're longer or shorter than what your eye can detect. Those are radio waves, microwaves, heat waves, ultraviolet waves, X-rays, and gamma rays. They're all the same thing as light, but they have wavelengths that our eyes can't detect.
Our eyes can detect a "band" of wavelengths in a range of about 2 to 1 ... the longest wavelengths we can see are about twice as long as the shortest ones we can see.
When we see different wavelengths, they look like different colors.
-- The longest light waves we can see are around 32.6 thousand in 1 inch, and they look deep red.
-- The shortest light waves we can see are around 65 thousand in 1 inch, and they look bright violet.
ALL of the other colors that humans can see are in between those limits.
When ALL colors of light get into your eye at the same time, the light looks WHITE.