yes it is possible to use DDR800 on DDR667 motherboard. But to be certain please check you motherboard spec.
DDR or SDRAM
It supports ddr (first generation - ddr1).
These are different and unrelated terms. SATA is a bus for connecting data storage devices to a motherboard. DDR is a type of memory.
cpu
Yes, DDR 400 memory will work in that motherboard, however only at a maximum speed of 333MHz. The memory will be underclocked to the maximum speed the motherboard can handle. Be sure not to try to put in DDR2 memory, as they are physically different and will not fit.
cpu
667 MHz
Chipset and CPU define the type of memory.
What memory your motherboard can use will depend entirely on your motherboard. There is no way for someone to answer a generic question like this.I can add a personal note that I did upgrade my dad's laptop to contain one 1GB stick as well as the 512MB it came with. Of course, I have no idea what motherboard it has (or even what manufacturer it is).
No. A motherboard will specify what type of memory it supports. The DIMM slot for DDR,DDR2 and DDR3 have different footprints.
Standard (DDR, DDR2, DDR3 as it must be the same as your motherboard) Speed (800, 1066, 1333 again must match the motherboard for optimization, can't exceed it) Size/capacity (GBS, # of sticks)
No, you can't use sd ram on a motherboard that specifies DDR memory and vice versa. It matters in terms of speed which type of memory you use, DDR is faster.