This is related to themeing your website, group similar topic web pages into different sections, create a sub folder to contain the group of web pages, give the sub folder a meaningful name that can well describe the group, and create a sub navigational structure for this group of web pages.
For example, your website is about fruits, your main navigation structure will likely be :-
Orange --> pointing to sub-folder (orange) with all web pages related to orange
Apple --> pointing to sub-folder (apple) with all web pages related to apple
In sub-folder orange, other than the main menu, create a sub menu for the web pages within the sub-folder orange :-
Introduction to orange
Types of oranges
Orange and healthy lifestyle
A day an orange, lucky all day
With a friendly structure like above, readers will have less problem getting to the information within your website, as well as helping the search engines understand better of your entire website theme and make it easier on the indexing process.
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