Can I plug DDR5 RAM into the DDR4 motherboard socket?

No, this implies DDR4 and DDR5 are not the same and there are no different RAM slots on a motherboard

DDR4 is not backward-compatible with DDR3 so a DDR4 DIMM will not fit on a DDR3 DIMM slot Not only is the key notch of each DDR generation

candibet slot The memory sub-system is interesting While the board supports both DDR5 and DDR4, there's only one of each slots, so you're limited to single-

can i put ddr3 in ddr4 slot But it's generally not recommended to mix different memory sticks because you can't be sure without testing If three stick config works without