This post gives the difference between related and relatable by comparing the definitions.
related is standing in relation or connection while relatable is possible to relate; able to be related to.
This post gives an nice example of related and relevant
math.stackexchange is related to ell.stackexchange
as they're both StackExchange sites, however,
the one is probably not relevant to the other in terms of content
as the topics covered by each site probably don't overlap much.
Could someone give similar examples to compare the difference between related and relatable?