Can we install DDR3 and DDR4 RAM in DDR2 RAM Slot

How to install DDR4 RAM on DDR3 Motherboard ddr3 slot Buy modDIY DDR1 DDR2 DDR3 Memory Slot Protective Jack Cover for $ with Free Shipping Worldwide ddr3 slot Is it DDR3 or DDR4? How many DRAM slots are available on the motherboard? Do modules have to be installed in pairs, triplets or quads? At what speed do you

ddr3 in ddr4 slot DDR3 modules have 240 pins, a DDR3 module does not fit in a DDR2 or DDR4 memory slot Figure shows DDR3 DIMMs Notice in Figure the metal casing