Text fragments allow linking to any text on a page, not limited to <a name="anchorname"> anchors or elements with an id="anchorname" attribute.
To achieve this it introduces the special #:~:text=... prefix which browsers recognize and navigate to the text on a page.

https://example.com#:~:text=[prefix-,]textStart[,textEnd][,-suffix]

The simplest case is to just use textStart:

https://blog.x-way.org/Misc/2024/12/27/Scheduled-Screenshots.html#:~:text=GitHub%20Action

example link

By using the textEnd we can link to a whole section of a text:

https://blog.x-way.org/Misc/2024/12/27/Scheduled-Screenshots.html#:~:text=steps,per%20month

example link

And with prefix- and -suffix we can further control the exact location when there are multiple matches:

https://blog.x-way.org/Misc/2024/12/27/Scheduled-Screenshots.html#:~:text=blog-,screenshots

example link

https://blog.x-way.org/Misc/2024/12/27/Scheduled-Screenshots.html#:~:text=screenshots,-repo

example link

There is also a corresponding CSS pseudo-element which can be used to style the linked to text fragment on a page:

::target-text { background-color: red; }

(via)