Peotic

I saw the great and beautiful movie "Badlands". In some part of it Hollie, one of the two main characters said that they lived neither here or there. That they were all alone. Then Kit, the other main character, replies (at least, that's implied in the voice-over by Hollie) that solitude would be a better word. But why? What's the difference between these words? Between loneliness and solitude? In Dutch there is only one word: eenzaamheid.