Mendeley  is a tool to manage and work with papers. I was looking for a way to read papers effectively. And it can be good for that. It's to import PDF files, and parse the metadata, and add annotation on the paper. I like the function of highlighting and commenting on a part of a paper.
Mendeley has the website, browser plugin, and desktop app for Windows, Mac and Linux. It was bought by Elsevier. To start to use it, you need to create an Elsevier account. Then in my case, I connected the account with the organization Czech National Library of Technology (see this past blog  to access the paid paper network. Then install the browser plugin. It's useful.
My typical use case to read a paper with Mendeley is to access the paper site (the PubMed page or the paper site), then click the Mendeley web Importer icon on the browser toolbar, and add it, and access it, and use a highlight text function, and add comment. I would prefer the web site version over the desktop app, because I can use Firefox's English translation plugin too.
After researching reference management tools , I find Mendeley, Zetero  and EndNote are popular. As Mendeley is proprietary, and Zetero is open source, I want to try Zetero later too. EndNote is a paid web system and app.
-  https://www.mendeley.com/search/
-  https://en.wikipedia.org/wiki/Mendeley
-  https://junaruga.hatenablog.com/entry/2022/03/07/040404
-  https://en.wikipedia.org/wiki/Comparison_of_reference_management_software
-  https://www.youtube.com/watch?v=8hx9qY7efgg
-  https://www.youtube.com/watch?v=KCqKW51vtKQ
-  Zetero https://www.zotero.org/