That works but you can inadvertently duplicate content across multiple pages.
The short answer is.
Is "Create New Section"
Name it whatever you want.
Copy, Paste the section code you want into your newly created section.
In the page you want the sidebar function to happen.
Write the code that calls for the section. The one you just made.
Same format with different name allows it to be edited as an independent entity on your webpage.
I hope this clarifies the process.