Difference in NetworkImage and Image.network?

Are there any difference in both of them?

Yes. They are different.

• NetworkImage class creates an object the provides an image from the src URL passed to it. It is not a widget and does not output an image to the screen.

• Image.network creates a widget that displays an image on the screen. It is just a named constructor on the Image class(a stateful widget). It sets the image property using the NetworkImage . This image property is used finally to display the image.

  class Image extends StatefulWidget{
    Image(...){}; //default Constructor
  
  
    //the argument src is passed to the NetworkImage and assinged to the image property
    Image.network(String src, {...}) : image = NetworkImage(src, ...);
  
  
    final ImageProvider image;
  
    @override
    Widget build(BuildContext context){
      display the image
      return RawImage(image: image,
        ...
      );
    }
  }
  

Whats the disadvantage and which one is easier to use for normal situation?

There is no disadvantage. You should use the one the suits the need. For example consider:

1. CircleAvatar widget that displays acircle that represents a user takes backgroundImage. It requires an ImageProvider. So you pass NetworkImage(http://image.com)
2. FadeInImage that displays a placeholder while the original image is loading also takes a ImageProvider for its image property. So you can provide it NetworkImage(http://image.com).

If you just want to display the image as a widget on screen use Image.network and use NetworkImage wherever an ImageProvider is expected.