Dd is not a disk writing tool (2015)
Yes "D" is not for disk/drive/device/...It comes from the DD (data definition) statement of OS/360 JCL, and hence why dd has the unusual option syntax compared to other unix utilsBTW if you are using dd to write usb drives etc. it's useful to bypass the Linux VM as much as possible to avoid systems stalls, especially with slow devices.
You can do that with O_DIRECT. Also dd recently got a progress option, so...    dd bs=2M if=disk.img of=/dev/sda... status=progress iflag=direct oflag=direct

Note dd is a lower level tool, which is why there are some gotchas when using for higher level operations. I've noted a few at:http://www.pixelbeat.org/docs/coreutils-gotchas.html#dd