Below is a comprehensive article regarding the acquisition and installation of macOS X 10.11 El Capitan, focused on safety, legitimacy, and technical requirements.
: A system-level graphics technology that improves rendering efficiency and speed for games and high-performance apps. using that download? OS X El Capitan - App Store - Apple mac os x 1011 el capitan iso download link
To create an ISO file, you'll need a third-party tool. Here are the steps using TransMac: Below is a comprehensive article regarding the acquisition
hdiutil create -ov -format UDRW -volname "El Capitan" -size 7g -fs HFS+ -srcfolder /Applications/Install\ macOS\ El\ Capitan.app focused on safety