Think of Disavow links as someone saying “Hey, you don’t have the right to step your foot in my lawn.”
More technically, disavow as used in the SEO world refer to (mostly harmful or low-quality) links you have ‘disallowed’ from pointing to your site.

As a webmaster, it is necessary to keep your website safe from malicious links pointing to it – as that is likely to affect your website ranking negatively.

SO, how do you find links you believe are harmful to your sit?
The procedure involved checking for inbound links in your site’s dashboard. You could measure the quality of each link and detect if it’s spammy or not – then disavow those links. Or in other words, stop their entry (and possible damages) to your site.

However, to disavow low-quality backlinks getting into your site, you need to use a tool. Don’t worry. It’s an easy to use tool made by Google.

The “Disavow Links Tool,” allows you to remove a list of links you suspect could be harming the SEO of your site.
It is designed to be easy to use. What the “Disavow Links tool” does is, tell Google web crawler, “Hey, I don’t want you to look at this link when checking out my website.”
Nonetheless, this tool should be used with caution. Else, it is not difficult to remove high-quality backlinks to your website. In fact, it is even more ethical to contact the webmaster of a particular site and inform them of your need to remove/disavow their link from your website.

On a more friendly note, you shouldn’t disavow links simply because they have lesser authority than your websites’. Disavow should be used for links that are spammy, prone to hack, or unsafe.

Disavowing low-quality links can help you keep your website ranking safe, or even in some cases, boost your ranking.

Always ensure to audit your website to keep it safe.