You're confusing a lot of terms. Here's some definitions to help you out:
Open Source - The copyright owner has allowed people to view and modify the source, create derivatives, etc...
Closed Source - The copyright owner has not provided these privileges
Commercial Software - software written for money. Believe it or not, a LOT of open source projects fall in this category.
Consider books. I buy a book, I can open the book. Having opened the book, and assuming it's in a language I understand, I can read the book. All the words are there for me to view. I still can't make copies of the book and sell them or give them away (depending on jurisdiction). In this regard, the book is Closed Source.
On the other hand, many books and articles distributed under a Creative Commons license (depending on options) CAN be copied and given away legally. These books, being no different from Closed Source books as far as readability is concerned, are Open Source.