Breadcrumbs are a navigation aid commonly found on websites. They appear as a horizontal trail of links, usually near the top of a page, showing your path from the homepage to your current location. The name comes from the fairy tale Hansel and Gretel, where breadcrumbs were dropped to leave a trail back home.

Their primary purpose is to improve user experience and website usability. They help visitors:

• Understand their location within the site's structure.
• Navigate upwards to broader categories without using the "Back" button.
• See the hierarchical relationship between pages.

There are three main types of breadcrumbs:

1. Location-based: Shows where the page sits in the site hierarchy.
2. Attribute-based: Used on e-commerce sites, showing product attributes (e.g., Men > Shoes > Running).
3. Path-based: Shows the exact steps the user took to arrive (less common).

For website owners, breadcrumbs also provide SEO benefits. Search engines like Google use them to better understand site structure, which can lead to rich snippets in search results, making your listings more attractive.

In short, breadcrumbs are a simple but powerful tool that reduces user frustration, decreases bounce rates, and supports your site's overall findability. Implementing them is a best practice for any content-rich or e-commerce website.