WHAT DOES THIS MEAN? 8GB or 4GB? which is better?

What does this mean?

DDR3L 1600 MHz SDRAM, 8GB, On-board Memory 4 GB, 1 x SO-DIMM socket for expansion up to 12 GB SDRAM

and

1600 MHz DDR3L SDRAM, 4 GB Memory slots 2 SODIMM

which one is much more better?