Could someone explain what this C# code is doing?

// launch the camera capture when the user touch the screen
this.MouseLeftButtonUp += (s, e) => new CameraCaptureTask().Show();

// this static event is raised when a task completes its job
ChooserListener.ChooserCompleted += (s, e) =>
{
    //some code here
};

I know that CameraCaptureTask is a class and has a public method Show(). What kind of event is this? what is (s, e)?