Today I came across the word "deflagration" - (noun form, naturally, of deflagrate - To burn or cause to burn with great heat and intense light - AHD). This prompted me to look up conflagration (A large destructive fire).

So - which one's bigger? I've always thought of conflagration as about as big as a fire can get, but perhaps I've just never come across a deflagration.

Does anyone actually use deflagration (I came across it in a fairly technical sense)? Is a deflagration not necessarily destructive, but a conflagration is, by definition?

Also noted that deflagrate exists, in both transitive and intransitive senses, but conflagrate seems to have burnt itself out over time.