Acrobat Services: PDF Services API

I noticed that cloud storage was showing that I had 40 GB available instead of the 20 GB I was expecting, so I looked at my account, and I saw that I was seeing another plan, Acrobat Services: PDF Services API, in addition to the Photography plan.

I don't remember seeing anything about this, or making any choice to get this to appear.

Is there any information about this?  I want to make sure that I haven't accidentally done something that I will be charged for.  Thank you for any information you can provide.

Robert