Details are a kind of information.
They contrast with summary or overview information in that they provide supplemental information not necessary for a general understanding of the matter.
Dividing information into a summary and details is not the only possible division, nor in many circumstances the most appropriate. For example, sometimes details can be crucial for acting upon a piece information (for example, the exact time of an army's attack), and some summary information may be irrelevant in a particular circumstance.
Trying to divine the context of your question, I suspect that these are headings in some computer software, maybe a scheduler or calendar. I also suspect that the heading information is being used (somewhat erroneously) to mean summary information.
If this is the case (more context would be helpful), then you need to decide, for the information provided, what would serve as a summary for those glancing at the schedule, and what can be somewhat hidden as a detail for the truly curious.
This is a property not of the various kinds of information themselves, but the use to which you expect them to be put in your particular case. If your scheduler is for the owner of a nightclub, the summary may be the date and time, the rest being details; if for a provider of party requisites, the date and reason may be the most appropriate summary; if for a social calendar, the date and reason; and so on.