In what way is Ruby on Rails NOT multithreaded?

Disclaimer: I’m a c# ASP.NET developer learning “ROR”. Sorry if this
doesn’t “get” RoR, any corrections greatly appreciated!
What is multithreading

My understanding of “multithread” ability in web apps is twofold:

Every time a web/app server receives a request it can assign a

thread to the new request, thus multiple requests can run concurrently.
The app runtime + language allows for multiple threads to be used
WITHIN a single request (in ASP.NET via “Async” methods and keywords for

In this way, IIS7 + ASP.NET can do points 1 AND 2.
I’m confused about RoR

I’ve read these two articles and they have left me confused:

Clearing up some things about LinkedIn mobile’s move from Rails to

How to deploy a multi-threaded Rails app

question one.

I think I understand that RoR doesn’t lend itself very well to point
number 2 above, that is, having multiple threads within the same
request, have I got that right?
question two.

Just to be crystal clear, RoR app/web servers can also do point number 1
above right (that is, multiple requests can run concurrently)? is that
not always the case with RoR?

What about this? - Ruby - Multithreading
Everything is very simple.