What is this Iron Maiden band we speak of? Do they matter? Yes.
For those of you unfamiliar with heavy rock and heavy metal in the late 70s and early 80s...
If you wish to give yourself a quick history lesson:
Browse from 1971-to-1989 on the "top-10" lists on this site and notice what bands come up. It suggests how FEW options there were for heavy rock or metal until 1979. http://www.bnrmetal.com/v5/topten/intro -- notice that you can't even fill out a top-10 until 1979 when heavy rock is surging.
Super short version of the story:
Iron Maiden was the KING of the heavy-rock/metal world from 1980-1983. Four years is a LONG time in the music industry to be on top with no competition. Slayer, Anthrax, Metallica and Megadeth (thrash metal) took things in a new direction in 1983 and got real traction in 1984 forward. Iron Maiden got left in the dust by 1986 -- but they have stayed relevant with their fan base to this day.
Those of us who grew up on heavy rock/metal cannot forget the impact, excellence, and reign they had during this four year period. Just like the impact of early Black Sabbath, or Led Zeppelin -- their first 5 albums are all masterpieces.
So in short, not knowing who Iron Maiden is -- would be like not knowing who Deep Purple is, or Led Zeppelin.
(beatles, rolling stones, the who) -> (led zeppelin, black sabbath, deep purple) -> iron maiden -> (metallica, slayer, megadeth) -> etc...
They are part of the progression of blues rock, into heavy rock, into heavy metal.
Today we have 100+ sub-classes of heavy metal and that would require an entire encyclopedia of pages to explain.