Chunks is for theme developers that have their themes filled with footer notes, copyright notices, block titles and descriptions, slogans, etc, which are sometimes hard-coded into the theme, sometimes localized (can be changed in po and mo files) and sometimes taken out to the theme options.

Chunks will do the job for you. A “chunk” is a piece of HTML code that could be inserted anywhere in your theme and edited from the Theme Chunks page under Appearance in your admin panel. Use register_chunks() in your functions.php to register chunks for your theme and use the chunk() to get the chunk value anywhere in your template files.

It’ll take you 5 minutes to implement Chunks in your theme: Getting Started with Chunks