Apple releases fourth public beta of OS X 10.11 El Capitan
Apple doesn't provide any details as to what's been updated in the new beta, but the company does recommend that all beta users install the update. To do that, all you have to do is launch the App Store, click on the Updates tab, and when it appears in the listing, click the Update button. Your Mac will need to restart.
Have no clue as to what this beta stuff is all about Read our El Capitan beta FAQ. You can still sign up for the El Capitan beta program, but remember, it's beta software and it's possible that you'll encounter bugs and problems with your apps and hardware, which is why you should provide feedback when using the beta.
If you've been using the beta and you don't want to anymore, you can revert back to Yosemite.
Don't want to try the beta, but you want to learn about El Capitan's new features We have a bunch of first look articles you can read: