ESXi comes in two flavours, "ESXi Installable" and "ESXi Embedded". But what exactly is the difference? Is it only the media ESXi is installed on? Like installing ESXi on flash/sd or usb is called embedded and ESXi installed on hd is called installable?
I have downloaded the HP ESXi4.1 installable and it is called "ESXi HD-USB-SD Image Installer" so it can be installed on hd, usb and sd.
Functionality wise they're the same product. Initially with ESXi 3.5, Installable could only be (officially) installed to hard disk and Embedded came pre-installed with the host on a flash device. With 4.0 you can put Installable on a flash device and given the push towards scripted installs and running stateless (see the Autodeploy project) I would think that VMware would drop the suffixes and just have ESXi in the future.
Even with vSphere 5.0 WMware didn't drop the suffixes.
So what's the difference ? In the WMware Compatibility Guide vSphere 5.0 with ESXi is supported, but not with ESXi installable...
Dave covered the differences.
All features/functionality are the same.
Embeded usually comes pre-installed on flash from the vendor. All you have to do is power on and setup.
Installable you can download and install on HD, USB, SD, SAN storage.