Ask HN: What Is a CTO Org?

I just got an email from a recruiter from a large-ish (mkt cap ~$10B) tech company asking me to apply for a Senior position in their “CTO Org”. I’ve never heard of this before. I can kind of guess that it’s some small group that reports to the CTO, but I’m curious what the dynamics are of something like this. Has anyone done something like this before?

FYI, I’m at a (well-known) startup right now, and the largest company I’ve worked for had ~$5B cap.