Bootable USB drive: You can use the ISO image to create a bootable USB drive, which can be useful for troubleshooting or installing the operating system on multiple Macs.
Virtual machine installation
this will save the installer straight onto your mac. approach 3:utilize a third-party site there are several third-party websites that provide mac os el capitan iso images for download. however, be wary when using these sites, as they may not be official or secure. install and usage after you've downloaded the mac os el capitan iso image, you can use it to: Mac Os El Capitan Download Iso Image