The light is dispersed so much so that everything has a soft look to it. There are no shadows and no bright spots. Perfect for portrait photography. As long as it doesn't rain and get you wet. It's also a good time for close ups.
Indoor light is very different and is more difficult to take good photos.
It consists of many different types of light. Some of them are fluorescent, tungsten and halogen just to name a few. Which can produce an ugly green or yellow tint to your photographs. This can be very annoying. Like at a birthday party or other gathering indoors where you have to take photos with available light.