This is the page if anyone wants to check if its real: https://scalacube.com/blog/terraria/how-to-stop-corruption-in-terraria
This is the page if anyone wants to check if its real: https://scalacube.com/blog/terraria/how-to-stop-corruption-in-terraria
You can defeat both crimson and corruption before they even begin by using a custom world generator that generates the world without it at all.
If you’re a masochist you can also create a world with both, or even one that is entirely crimson or corrupted.