Fading to black means stopping. It's a period mark. An end point. The story is over. Fading to white? It can be used to mean so much more. It could be the end, but it also doesn't have to be. It could be hopeful and enlightening and happy. But it could also be sad. Here's a compilation of fade to white scenes in movies.
Put together by Jacob T. Swinney, he explains:
What does it mean when a film fades to white? When a film ends with the more traditional fade to black, there tends to be a sense of closure. On the other hand, ending with the much less common fade to white seems to create a sense of ambiguity. When not used at the end of a film, fades to white are often used to express disorientation and euphoria, among many other similar sensations. Here is a look at a variety of films that utilize the fade to white for a variety of purposes.