A bio link is the URL in the website field of a social profile. The term also names the page that URL opens, which lists your other links.
"Bio link" means two related things. The narrow meaning is the URL itself, the one you paste into the website field of Instagram, TikTok, or another app. The broad meaning is the page behind that URL.
People often use "bio link" and "link in bio" for the same idea. "Link in bio" is what you say in a post. "Bio link" is the thing you set up.
A short, readable bio link is easier to say out loud in a video and easier to type from a poster. That is why many people use an address built on their username or their own domain.
Example
A designer's bio link is pageo.me/mara. On Instagram, TikTok, and LinkedIn the same URL opens the same page, so one change updates every profile.
In pageo
Your pageo bio link is pageo.me/ followed by your username. You can change the links on the page at any time, and the address stays the same.
Links and pages
Link in bioA link in bio is the single clickable link in a social media profile. It usually points to a page that holds all of a person's other links.Read the definitionLinks and pages
Vanity URLA vanity URL is a short web address built around a name or a brand, such as site.com/name, that is easy to remember, say, and type.Read the definitionDomains and search
Custom domainA custom domain is a domain name you own, such as yourname.com, that you connect to a service so your page loads at your own address.Read the definitionClaim your page in under a minute. No card needed.