Ask HN: How do you organize or bookmark your content?

How do you organize/bookmark/index your visited websites and the content you liked to retrieve it efficiently in the future? Do you use any special tools to do it?

I have been finding it very difficult to track this. I always remember that I want to pull up something interesting that I read but never able to find it back. Sometimes I search by keywords which I vaguely remember in Google and it shows up, but mostly there I don't remember what I am searching for and it becomes very difficult to keep track of everything. This gets even more painful if you are researching on some topic and you follow trail of links to reach something. That article might not be on top of the search engine indexes but might have something that I am interested in. How do you retrieve such content/websites when you suddenly close all your browser tabs?