 <p>The part you are asking about is an anonymous method that uses a lambda expression. It is commonly used in callbacks.</p> <p>When you write this</p> <pre><code>(machine, error) =&gt; { SelectedMachine = new MachineViewModel(machine); } </code></pre> <p>you are making a function that has no name (and therefore cannot be reused by name, like a regular method). It is very convenient in situations when you need to produce a piece of callable code that needs to be used only once, e.g. in callbacks.</p> <p>Note that the method does not have to be anonymous: you could make an equivalent named method. However, an since the anonymous method is built in the context of the method where it is used, the variables from the context are available to it. Your anonymous method assigns <code>SelectedMachine</code>, which is probably a property of your class. In the same way, anonymous methods can access local variables as well, which is a very powerful mechanism of combining together a state and a piece of code that operates on it.</p>