Some websites disable copying, right-click or text selection to discourage copying content, which also blocks legitimate uses like grabbing a quote, a code snippet or an address. An allow copy extension overrides those scripts so you can select and copy text again, typically with a single click on the toolbar icon.
Why some websites block copy and right-click
Sites disable copying and context menus with small JavaScript snippets, often to discourage content scraping or to protect paywalled text. This also blocks normal actions like copying a phone number, a recipe or a code example. An allow copy extension counters this by disabling those scripts on the page you are viewing.
Copy protection vs right-click blocking
Some sites only disable right-click while leaving text selection and Ctrl+C working; others block selection entirely with CSS or JavaScript. A good allow copy extension restores both text selection and the right-click menu, since a fix for one does not always fix the other on every site.
Using it responsibly on a site-by-site basis
Enable the extension only on sites where you need it, rather than leaving it active everywhere, since it changes how a page behaves. Respect copyright and a site's terms when copying content; the extension restores a browser feature, it does not grant permission to republish protected text.