Difference between `/sdcard`, `/storage`, `/data` and `/storage/emulated`

Files, for example photos taken, I can using either

  • /sdcard,
  • /storage (respectively also /storage/emulated)
  • or /data (respectively also /data/user/[uid])

can somebody provide an answer that shows the relationships, and differences those pathes.

Bonus: it does not seem that data is always stored with same access rights on the beforementioned paths, how comes?