Isolates are separate execution threads that
do not share any memory with the main execution memory heap.
This is a difference between Task.Run().
This means you can’t access variables from the main thread,
or update your UI by calling setState().

The following example shows, in a simple isolate,
how to share data back to the main thread to update the UI.

Here, dataLoader() is the Isolate that runs in
its own separate execution thread.
In the isolate, you can perform more CPU intensive
processing (parsing a big JSON, for example),
or perform computationally intensive math,
such as encryption or signal processing.

You can run the full example below:

How do I make network requests?

In Xamarin.Forms you would use HttpClient.
Making a network call in Flutter is easy
when you use the popular http package.
This abstracts away a lot of the networking
that you might normally implement yourself,
making it simple to make network calls.