I could be wrong, but cold crashing generally takes place over a few days prior to bottling. Cold conditioning pertains to ales (lagering for lagers) and is held at the cold temperatures for a week or more.
The idea of either method is to help the yeast flocculate better and settle out any suspended particles, so as to end up with clearer and smoother tasting beer in the bottles. I think cold crashing is more about trying to clear up the beer by settling the suspended materials, whereas cold conditioning does the same, plus it promotes a smoother, crisper taste in the beer.