This is a link building tactic that includes you searching for web pages that mention your brand, service, product or personal name, without linking to you. You then reach out to these websites (or those that are relevant and have a decent domain authority to be precise) and have them add a backlink. This is a tactic that has a high return on investment as the chance of the website you are contacting giving you a backlink is very high.
You can use Google Alert to track any mention of your brand, service or product.