They are not the same thing, but they are close.
Curly hair tends to have tighter curls, so the hair would be more bouncy. Beyonce’s natural hair is an example of this, as her hair in its natural form looks like coils.
Wavy hair is in between curly and straight hair. Instead of being very tight curls, wavy hair is looser but still has some roundness to it. It is where most people’s hair falls, especially if it is longer. That is because the weight of your hair could stretch it out, making the spirals less tight.
There is no definite difference between curly hair and wavy hair. The difference, especially for hair that is in between these two descriptions, often depends on what the person whose hair it is says. In addition, while you typically use a hair curler to make your hair have spirals, if you originally have straight hair you will probably end up with wavy hair rather than curly.
No, ‘wavy’ and ‘curly’ hair aren’t the same thing but you’ll often hear ‘wavy hair’ and ‘curly hair’ being used interchangeably to describe a person’s hair that isn’t straight. However, these two adjectives ‘wavy’ and ‘curly’ aren’t describing exactly the same type of hair.
If somebody have wavy hair, this means that his/her hair isn’t completely straight but it’s not very curly either, they have loose curls. Whereas, a person with curly hair usually has tight curls as opposed to loose curls or waves. These tight curls are usually a lot closer to the person’s head.