Page 2, chapter 1. Source Control & Why you need it, section 1.3. Source control description, subsection 1.3.1. Check out systems, last but one sentence of the page, it’s written:
“They can get a read-only copy so they can say build software but only the ‘owner’ can edit it.”
The part emphasized is incomprehensible there, and I didn’t understand what it is supposed to mean in fact.

It seem to me that the "say" word is not supposed to be there and, therefore, the sentence should be:

They can get a read-only copy so they can build software but only the “owner” can edit it.