I love sunsets. They are so beautiful and seem to never be the same which keeps them intriguing.
They may look different because they set in a different place every day and will set on due west on the spring and fall equinoxes. 
That would make sense. My favorite are sunsets at the beach. Nothing better than that.
Yeah a sunset doesn't technically happen until the trailing edge of the sun disappears 
I always assumed once the colors started changing that was technically the sunset. What else do you know about them?
Your thinking of twilight which has three different phases, civil, nautical, and astronomical. 
Oh ok, do you know what each of those phases entails? 
Well civil begins once the sun disappears below the horizon, nautical is when the sun is betwen 6 and 12 degrees below the horizon and beyond that is astronomica. 
Hmm I always looked at sunsets as just that, sunsets. I didn't realize they had phases or anything like that.
Yeah and even beyond twilight is dusk which is the darkest moment before night.