Categories and Tags come real handy for organizing posts on WordPress website. However, by default the option of categories and tags for Pages in not available in WordPress. Fortunately, you can enable categories and tags feature for Pages and make them behave like Posts on WordPress.
Add Categories & Tags feature to WordPress Pages
Post Tags and Categories for Pages plugins seamlessly adds this feature. Once you activate the plugin, goto Pages section to see new “Categories” and “Tags” options just like they appear under Posts section. There is no setting to configure. While writing new Page content, you can select and assign new category / tag to specific page(s) in WordPress.
Pages are Posts is another plugin with similar functionality. It makes WordPress Pages behave like Posts by adding tags and categories option. This plugin does not alter database and adds this functionality using hooks. It also promises to work fine on multi-site installation.
Why would I need category / tags on WordPress Pages
You can create as many posts as you like but creating too many Pages is not recommended. However, if you have created lot of pages – then tags and categories in pages feature should help in organizing pages content just like posts on WordPress site.