It's a feed protocol for websites. Each time you see that icon, it's a RSS feed :

You have a RSS client, a program you use to display your news. In it, you paste the url of the RSS feed of the various websites you want to follow, and just like that, you have an app in which you can go every morning to see what's new in your favorite websites, all at once.

Now, the problem of course is that not every website, by far, is offering RSS feeds, so you have to look for those who provide one. RSS is popular among techies and journalists, so press and tech blogs are where they are the most common. On top of that, there are many websites having RSS feed without even knowing it, because they use Wordpress or other engines that automatically provide RSS feeds. Those are a bit more tricky to get your hand on, because there is no link anywhere on their page, you have to look in the source code of the page (using Control + u) to find an "alternate rss" or "atom" link. It used to be automatically detected by browsers, showing an icon in the url bar when a RSS feed was detected, but it's not the case anymore. You can still install a browser extension to make them appear, like this (chrome) or this (firefox).

For the record, youtube has RSS feeds for all publishers, reddit has RSS feeds for all subs, most major news websites have RSS site, so it's quite useful, provided you can find the feed urls.

Then, to actually aggregate the news, you need a RSS client in which to paste those feed urls. There are tons of them. Name your favorite platform, there probably are a dozen RSS clients for it. Mobile, web, desktop, it's everywhere. So pick the one you like best. :) You just have to search for "RSS client for ". A couple popular exemples : The Old Reader on the web and Thunderbird (which is also a mai client) on desktop.