When a hairstylist refers to the 'texture' of your hair they are talking about specific variables.
First is the wave pattern of your hair, wether you have one or not, think straight, wavy, curly or coils. Now remember, hair is not one size fits all! Your hair may be straight but still have texture to it.
Second, the texture of your hair can also refer to the words fine, medium and coarse. Fine hair tends to be smoother in texture and a single strand of hair is small in diameter. This is not to be confused with how many hairs you have on your head, that is density.
Coarse refers to the diameter of a single strand being larger than average, or for reference, larger than sewing thread. Medium is somewhere between the two, your hair strand isn't particularly thin or thick (again referring to size of single hair strand, not how many strands you have on your head) than most likely we would assign you medium texture.
Pluck one hair off your head, roll it between your fingers. If you can't feel this single strand then most likely your hair texture is fine. If you can feel the strand in between your fingers as you roll it, chances are you are closer to coarse. A dramatic way to know you have coarse hair is if a single strand is closer to the diameter of dental floss than a sewing thread.
Some examples of vastly different hair textures:
Your hair can be straight and coarse, appearing sort of "wooly" in texture.
Your hair could be very curly but fine in texture, tangling easily and tending to lose a style quickly.
Your hair can be slightly wavy and medium in texture, this hair tends to hold a curl/style very well and be on the more manageable side of texture.
There are millions of different hair textures, this is the beauty of us learning your hair! The goal here is to learn your hair type and texture to curate your shipments with products that manage and celebrate your own personal genetic lottery.