http://weblogs.about.com/od/partsofablog/qt/Blog-Page-Overview.htm on 20March2017
What Is a Blog Page?
A blog page is typically a static piece of content on your blog.
Most often, pages are accessible through links in the top navigation bar of a blog, just like a traditional website. Popular blog pages include an About Page and a Contact Page.
Blog pages exist outside of your blog’s posts and related archives. They are most often used for content that you want visitors to have easy access to at any time. That’s why pages are often used to provide information about the blog and blogger and contact information. In other words, information that you want visitors to have one-click access to can be published through pages.
For example, a business website built on WordPress could create pages to describe its business, provide product pricing, publish testimonials and customer reviews, and more. A personal blog could offer pages that enable readers to learn more about the blogger’s background, contact the blogger to start up an offline conversation, and so on. In other words, it’s up to you to decide how you want to use pages on your blog and what information you want to provide on the pages that you publish. You can create as many pages as you wish; remember, these are pages and are different than posts.
How Are Blog Pages Different from Blog Posts?
Blog posts are the daily (or ongoing) entries to your blog. They’re published in reverse chronological order and are usually accessible through your blog widgets (archives or categories).
What are widgets? https://www.lifewire.com/what-is-blog-widget-3476276
Some blogging applications, like WordPress, use widgets to enable bloggers to modify the design and content of their blogs. Widgets are simple point-and-click or drag-and-drop systems and by this way, without needing to know any programming languages like CSS or HTML we can arrange the design of our blog. Widgets are most frequently used as blog sidebars. Each widget represents an area of content, which bloggers can fill with ads, text, links, images, and more. The blogger can simply modify the placement and content of the widgets in the sidebar by dragging-and-dropping or pointing-and-clicking.
If you want to present a content under your widgets (categories), you must:
(1) add that content as a post (not a page)
(2) select the category for that post
(3) publish your post.