There is no 100% correct answer to your question, however I will provide you with some rule of a thumb advice and hopefully you will be able to find the most suitable solution for your scenario:
You should create pages if you need navigation (like menu) for the articles (e.g. About us) or if the articles need to have different elements on the page. For instance, one article may need to have a download list on the right side of the page, while other article may need to have a search box on the right side.
If you have a lot of content that does not need to appear in sites navigation or if you want to create a list of content and then when you click on a particular link the full content should open (and page structure is always same) you should probably use one of the modules (generic content, blogs, news or a custom module).
So, the answer is: it depends. Probably you will use some mixture of the two approaches. Perhaps the articles for "about us", "contact", "mission", etc will be pages, and news articles will be content items inside of News module.
I hope you'll find this information helpful. Let us know if there is anything else we can do for you.
All the best,
the Telerik team
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