Here's a breakdown:

* ITU-T G.652 is a standard for single-mode optical fibers.

* G652D is a specific subtype of G652 fibers with lower water peak attenuation compared to other G652 variants. This makes it suitable for longer transmission distances and higher data rates.

So, while G652D is a type of fiber optic cable, it's not a standard itself. It falls under the broader G.652 standard for single-mode fibers.