What is the word for “Unnecessary detailed information”?

Question

Can you tell me what the word is for "Unnecessary detailed info on a topic which is given after the prominent parts is given"

Answer 1

You could say that it is extraneous:

not pertinent; irrelevant: an extraneous remark; extraneous decoration.

Answer 2

We could call it "information overload":

The inability to process everything one hears and sees; the availability or supply of too much information, or a state of stress which results.

"information overload" is the result of too much information, and perhaps, can be used to refer to the "too much information" itself

Answer 3

If someone doesn't stay on topic, you might say their unrelated information is a digression or that they've gone off on a tangent.

If they simply go on at length, they might ramble, drivel, blather, or babble, producing some form of nonsense, perhaps claptrap or prattle.

Answer 4

"Fluff" or, more negatively, "bloat"

Answer 5

Assuming you're referring to printed material of some sort, you might be referring to a 'disclaimer', 'statutory legalese', aka 'the fine print'.