How? With 301 Redirects.
What's a 301 Redirect?
A 301 redirect is a permanent redirect which passes between 90 to 99% of link equity (ranking power) to the redirected page.
Let me explain that in other words...
Say there's an old article placed on Forbes.com, with a link to another site in that post.
Imagine that link is pointing to a domain that no longer is active.
I buy and register that domain.
That site is now mine.
I registered the expired domain that the Forbes.com article links to, and I will redirect the newly registered domain (the expired domain) to your website.
I've made it so the expired domain redirects to your site.
So, when you click on the link on the Forbes.com article, you'll be taken to your site.
If you're interested, in learning more, click the link bellow!