Below is a picture from C# 7.0 in a Nutshell book:
[![enter image description here](https://i.stack.imgur.com/ORvRN.png)](https://i.stack.imgur.com/ORvRN.png)

Q1-from the picture, it can be inferred that only backing store streams e.g. FileStream can "connect" to files directly, but isn't that we can use StreamReader/StreamWriter to read/write to the file directly?

Q2-The book also says:

**An adapter wraps a stream, just like a decorator. Unlike a decorator, however, an adapter is not itself a stream; it typically hides the byte-oriented methods completely**

But isn't that StreamReader/StreamWriter etc labelled as Stream Adapters in the picture? how could they be called "Stream Adapter" if they are not considered as streams?