Laptop operating systems/ memory

I’m shopping for a laptop & all these numbers are confusing the heck out of me. What is the difference between 256GB SSD storage & 8GB 1866MHz LPDDR3 memory. What even is 8GB 1866MHz LPDDR3 memory? Would I want to go for the 16GB? I would mainly use if for everyday internet browsing, streaming & maybe photo editing. I have quite a bit of songs, movies, videos & photos. I would want it to run smoothly & have enough memory to last me a few years.