With Archives Content you will be able to easily add content to your archive pages from the WordPress admin panel.
Archive pages are pages that are automatically generated by WordPress to list a series of posts. For instance, a portfolio page (which lists a bunch of projects), a category page (which lists all posts belonging to that category) or a tag page (which works very much like the category page).
Ring a bell?
All these pages are dynamically generated and you have no control over them through your WordPress Admin panel.
What the Archives Content plugin allows you to do is to create a block of content to be inserted before the list of post in any archive page on your site.
For instance, you may have an “events” category in your blog and you may want to highlight that all the events on your site are free to attend. By default WordPress does not allow you to add any content to the “events” category page, but with this plugin you can!