Inevitably, these terms will get confused and misused. People will use one term when they mean another, or perhaps not understand the difference between two terms. And that's fine – after all, knowledge is relative. What one word means to you is not necessarily what it means to me. But I won't bore you with critical theory and philosophy today (I always get especially philosophical at 6 am, I have no idea why).
Let's look at a primary example of a word that is often misused or misunderstood conceptually. Fulguralis calls me a word nerd for a very good reason!
1. to lessen in force or intensity, as wrath, grief, harshness, or pain; moderate
2. to make less severe: to mitigate a punishment.
3. to make (a person, one's state of mind, disposition, etc) milder or more gentle; mollify; appease.
4. to become milder; lessen in severity.
Disc Priests are the king of damage mitigation amongst the healing classes, and I don't think there's any argument about that. However, I often hear of Druids being referred to as damage mitigators as well, and this grates on my word nerdiness, and does not accurately reflect the power of the HoT. If you say that Druids are damage mitigators, then it could be interpreted that a Disc Priest + Resto Druid is a poor healing combo for a ten man raid. This is absolutely untrue – Disc Priest & Resto Druid is a fantastic ten man healing combo.
I have been unable to find a term that adequately describes the purpose and power of the Druid HoT. The word for Disc Priest is, of course, mitigation, but I cannot conceive of a proper alternative for Druids. I understand, therefore, why people often refer to them as mitigative (lawl I will not be put off by that squiggly red line!).
The power of mitigation healing is that it reduces the impact of a big burst of damage, smoothing the incoming damage out a bit, taking off the peaks of pain. HoTs have this same power, but in a different way. Mitigation smooths out the incoming damage. HoTs smooth out the health pool. They result in similar effects, but go about it in different ways. Both Disc Priests and Resto Druids are "smoothers" if you will – but they are inherently different in their processes, and misunderstanding the difference can be fatal.
The fundamental difference between the two is best described in an example.
Let us say, for the sake of argument, that you have a tank with 35k health. This tank takes a hit of 37k damage, and consequently dies. A Disc Priest can actively prevent this by using one of their many mitigative abilities – be it Power Word: Shield, Pain Suppression, or perhaps a well timed Divine Aegis proc. These "mitigation" abilities are, in effect, temporary hit points that will be absorbed before any of the actual damage. If I pop a 5k shield on the tank, I have effectively increased their health to 40k, albeit temporarily. This is enough to allow them to survive that hit.
A resto druid cannot give that tank temporary hitpoints. However, if my Penance is on cooldown, a Resto Druid can do something that I cannot. What if, right after that tank takes that 37k hit, and is down to 3k health, he continues to take melee damage? With his health so low, and all my cooldowns blown, he could die before I get my Flash Heal cast off. But if he has HoTs on him, he will have health trickling in that may be enough to keep him alive between the time that he took his giant hit and the time that my Flash Heal or Greater Heal lands. THIS is the power of a Resto Druid.
Of course, in the effort to find the right word for teh HOTNESS that is a resto druid, the Twitterati came out and threw me a variety of potential words to meet my demands. None of them were perfect enough for me, but some of them were pretty epic.
Angelya again: Trickling?
Me: Trickle top-offing?
Sheqeri: Increased effective health?
Dristanel: Flailing? Foundation HoTs?
Matticus: Health gappiness?
Nibuca: Hottification? Pre-cognitive burst smoothing? Bursty effective armor displacement stamina throughput druid mob tree? (I get this strange sensation as if she were almost teasing me...)
Wonderful suggestions, eh? But I do believe that Deyndor takes the prize for the best suggestion of all time: Colander Heals. (I made sure I spelled it right this time! Ever notice that my spelling errors are mostly limited to double consonant words?) Do you have a difficult time conceptualizing Colander Heals? Well, LET ME DRAW YOU A PICTURE