Does the Buillt-in Apple Recovery Partition already have an OS X Image or does it download it over internet? I am asking because if it does download over the internet I want to create my own recovery partition from a Yosemite Install application.
It has to download. In favor of saving space on your hard drive, the Recovery HD is 650 MB of various utilities including one to download and reinstall OS X.
It has to download. You can make a bootable partition that installs macOS using the free Install Disk Creator. Just follow the instructions there on how to use it, but point it at a blank partition of 8GB or larger.