Here comes #3 of Charlie Jane Anders' "10 Writing "Rules" We Wish More Science Fiction and Fantasy Authors Would Break"...
3) Avoid infodumps
Like its cousin,
“show don’t tell,”
this injunction can be a
great idea but can also
get you into trouble.
Sometimes an infodump
can be a horrendous load
of backstory or technical
schematics, rammed down
your poor reader’s throat.
But at other times, authors can go to huge, insane lengths to avoid
having to come out and explain something. Like having contrived
conversations, or weird “teachable moments” to convey a basic bit
of worldbuilding to the reader, with the effect that the story grinds
to a halt.
We posted a collection of 20 well-done infodumps a while back,
just to prove it can be done well.
(I kept Charlie Jane Anders' links for reference)