Here is a question what is noble team and what halo unvirce do it take place and why did they die
Noble team was a squad made up of 5 SPARTAN-IIIs and 1 SPARTAN-II. They exist in the halo universe (there is only one universe in the series), and throughout Halo: Reach, one by one they are killed in the fruitless exercise of trying to save Reach, however their action go on to end up saving many others. Basically they died as a symbolic point to the brutality and hopelessness of war without over-glorifying their deaths. Each of their deaths is even symbolic in some manner or another. Jorge, the man who loved Reach and thought of it as his home, died in orbit around it. Kat, the brains of the team, got killed by being shot in the head by a Covenant sniper. Carter, the leader, died by literally going down with his ship. Jun, the sniper who preferred to stand back from the fighting, separated from the team to protect another person and ended up living. Emile, the knife expert, died with an energy sword through his chest. And finally Noble Six (you), the lone wolf, ends up dying alone against impossible odds. It's all quite poetic really. Hopefully this answers your question.
w̶h̶a̶t̶ Who is Noble Team?
- A group of Spartan III's who try to save Reach from a friggin huge Covenant invasion but ultimately fail and each die slow, painful, miserable deaths (except for Jun cause he was a little -no no word- and escorted Halsey off the planet)

What Halo Universe does this take place in?
- The only one that exists, which is the Halo Universe

Why did they die?
- Dunno, some died spontaneously (aka Emile backstabbed and Kat headshot) while others sacrificed themselves (Jorge, Carter, Noble 6).
Ahh I see and what did reach have in the halo universe
Ahh I see and what did reach have in the halo universe
I'm not totally clear on your question but I'll try to answer:

If you mean what it physically had: Reach was the heart of the UNSC and a major military industrial complex for the UEG. It was the home of the Spartan II program and was rich in titanium deposits, so a lot of the UNSC fleet was built from those raw materials.

If you mean what importance did it have to the story: Reach was considered to be on Earth's doorstep, so if it fell, Earth would fall soon after. This is what almost happened in Halo 2 when the Covenant showed up in the Sol System.