BK,
I'll try to explain another one.
The main purpose of a project is to deliver a product, per client's requirements (it might be a requirement from your organization, or a government request, but it's all similar). So we guide the team to do project work in order to deliver the needed product. Call it "guide the team", or "guide the project work", or simply "direct and manage project work". At the end of this process, after we all worked hard, we have the deliverables in our hands. These deliverables might be in a form of a report, a bicycle, a new book, or whatever the product of the project is. What are we going to do with, say the new book? We can't simply provide the client with the new book just like that. We have to verify its correctness. How's its quality? Let's control the quality of the book. Read it one time, read it ten times, study it, compare it with the initial plan, compare it to the customer's requirements, verify the book in order to look perfect for the client. So at the end of the Control Quality process, we should have the verified book ready to be presented. If it's not about a book, we may call it "verified deliverable(s)". Once we have the deliverables verified, we want to see what the client thinks of it. It might be accepted (Accepted Deliverables), it might be rejected with some modifications needed to be done (Change Request), but the product's initial scope should be validated. (in Validate Scope Process)
Summary: We collect the requirements (Collect Requirements process) -> We write down the purpose of the project (Define Scope process) -> We do the actual work in order to get the needed product (Direct and Manage Project Team process) -> We verify the deliverables (Control Quality process) - > We ask the customer whether he accepts these deliverables or not (Validate Scope process).
In my opinion, these are the steps to be followed to get the product of the project done.
BK, this thinking might be overwhelming to you, but I really hope you'll find your own way of understanding all these processes. Think like you are above all, somewhere in an invisible attic. You have a guy that asks for a new book, you have a bunch of people ready to help to create the book, you have a lady willing to pay for all this. What would you do in order to deliver the requested book?
Regards,
Cris Sirbu, P.E., PMP