El Capitan Installer is the post version to the Yosemite, and it was built by adding up more improvements to the Yosemite.
And it is named as ‘El Capitan’ after the formation of a rock in the Yosemite National Park. This is the very last version of the Mac operating system which comes under the name OS X. All the Mac computers which don’t have the privilege to upgrade to MacOS High Sierra or the computers that need to upgrade to El Capitan first, can download this twelfth version on the computer. Mac operating system’s twelfth major version is the El Capitan Installer (version 10.11).