Whether you choose indoor or outdoor lighting depends on your purposes. An easy way to think about it is If you plan to use them indoors, get indoor lighting. If you are going to use them outdoors, get some outdoor lights.
This becomes a little more complex when the lights are designed for use. Some lights are specifically outdoor lights, some are advertised as indoor lights, and some can be used for both. Carefully check the labels on the lights before buying them. You should indicate whether they can be used indoors, outdoors, or both.
The reason for the difference is that many outdoor lights are made with it heavier materials to stay longer, like all night. Outdoor lights are also built to withstand the elements. Indoor lights are more sensitive because they are not as exposed to electrical loads or elements. Attempting to use the lighting outside of the intended purpose can, in the worst case scenario, result in a fire. It is therefore a security problem.