Links at the top of a web page or in a search result, that better help the user navigate the site. Onsite links often appear near the web page’s title and look something like this: Home > Services > Specific Service.
Breadcrumbs can also be found in search results through specific schema markups. These help users find related pages from the search result listing.
in other words, It's an element on a page or SERP result that shows the navigational trail a user took or could take to reach the page they are on. On a webpage, the trail is a series of links to other pages and is most often located at the top of the page. Example: Home / Shop / Backpacks