Copy URL With Hash is a browser extension to copy a page's URL with a hash at the end that identifies the location on the page.
When building a web page, web developers can assign an ID to a specific element on a page. Then, they can use the ID to link directly to that element on the page. For example, Wikipedia pages have a Table of Contents; the links inside the Table of Contents take you to different parts of the same page. When you click or tap on an item in the Table of Contents, look at the URL in the location bar; the section of the page is identified in the URL by the hash (the part of the URL after the hashtag symbol: #).
Some sites provide an easy way to get a link to a specific part of the page; for example, on Wikipedia, you can right-click or long-press on an item in the Table of Contents and select "Copy Link Location" or "Copy Link" to copy a link to that part of the page. However, some pages have headings or other elements identified in the source code by a specific ID, but they do not provide an easy way (like a table of contents) to get a link to that ID. This is where Copy URL With Hash comes in; just right-click or long-press anywhere on a webpage (for example, on a heading), and, if there is a specific ID that represents the element on which you right-clicked or long-pressed, Copy URL With Hash will add a button to the context menu (labeled "Copy Page URL With Hash") that will copy the page URL to your clipboard with a hash at the end that will take you directly to that element on the page.
Using Copy URL With Hash is simple; just right-click or long-press on something that looks important (like a heading in a page). If the owner of the page included an ID on the element that you right-clicked or long-pressed on, a button titled "Copy Page URL With Hash" will appear in the context menu. Just click or tap this button to copy a link to this section of the page! Then, you can send that link to someone else, include it in a document, store it in your own notes, etc.
Try right-clicking or long-pressing on any of the headings on this page. Notice the "Copy Page URL With Hash" button? Clicking or tapping on it will copy this page's URL to the clipboard, including a hash on the end to identify the location on the page. Try pasting the copied link somewhere and comparing it to the URL of this page that you can see in the location bar to see the hash on the end with the location in the page.
The headings on this page include IDs, so Copy URL With Hash will work with them. However, this page is too short to be able to test its functionality well. For a better example, visit a Wikipedia page of a decent length. Try using Copy URL With Hash with any of those headings. After you copy a URL using Copy URL With Hash, try opening a new tab and going to the URL to see how it brings you to that section of the page.