What is uek boot iso image?

Oracle Linux 7 UEK Boot ISO image for x86_64 (64 bit), UEK is used during the installation and is the default kernel that is booted after an installation. This ISO image contains everything needed to boot a system and install Oracle Linux. This is the most common download. Oracle Linux Release 6 Update 4 UEK Boot ISO image for x86_64 (64 bit). For a full install you want to choose Oracle Linux Release 6 Update 4 for x86_64 (64 Bit). Boot ISO UEK image: Same thing, but with the "Unbreakable Enterprise Kernel Release" buzzword kernel included.