DDR is typically a bus with more than 1 DIMM slot per channel. LPDDR is typically point to point. Electrically, it's a lot easier to meet signal integrity req

DDR is typically a bus with more than 1 DIMM slot per channel. LPDDR is typically point to point. Electrically, it's a lot easier to meet signal integrity requirements on a point to point trace than it is to make a multi drop bus work properly.