What is the difference between = and => for a variable? [duplicate]

Question

What's the difference between these two ways to add something?

private string abc => "def";

And

private string abc = "def";

Answer 1

This is the declaration of a classic field as it has always existed in C#:

private string abc = "def";

The field is immediately assigned an initial value.

---

This is a shorthand syntax for declaring a getter-only property (or expression-bodied property), introduced in C# 6:

private string abc => "def";

It's a short way to write the following:

private string abc
{
    get { return "def"; }
}