My (inexpert) guess is that it's a 'Phalenopsis Type' of Dendrobium.
It is very unlikely you will ever get a full ID for it as there are so many hybrids, but that dosn't matter too much as long as you know the type.
If I'm right and it's a Phal type then it will NOT need a winter rest or loose it's leaves in the winter like some Dens do. So just keep caring for it the same way all year.
See here for a general care sheet for Dendrobium.
Dendrobium - Orchid Board