I (and this Wikipedia article) recommend the use of the of the word piquance (or piquancy) to describe the condition of something being spicy hot, such as chili peppers.
The article explains:
A pumpkin pie can be both hot (out of the oven) and
spicy (due to the common inclusion of ingredients in its recipe such as cinnamon, nutmeg, allspice, mace and cloves) but is not actually
piquant. Conversely, pure capsaicin is piquant, yet is not naturally accompanied by a hot temperature or spices.
To avoid ambiguity:
- Use piquant [pee-kuhnt, or pee-kahnt] to describe something that is spicy hot. (The Scoville scale measures the piquance of chili peppers according to the amount of capsaicin they contain.)
- Use spicy to describe something having the quality, flavor, or fragrance of spice. (Many curries are spicy without being piquant.)
- Reserve hot to describe the temperature of something.
The basic difference between the two is emotions it appeals to.
Fun is enjoyable. It causes pleasure - especially in active forms, as thrill, exhilaration, challenge, elation.
Interesting appeals to curiosity - learning, it's about things we want to know, see, learn, examine. Whatever reasons - be it for pleasure, or e.g. for professional interest or satisfying anxiety.
Since usually satisfying curiosity is pleasurable, these two are often correlated, but not always. A gruesome sight, say, bowels sticking out of a live person's ruptured abdomen, may be interesting, but definitely not fun. A secret document on enemy military movements will be interesting too, but definitely not fun. The pilot of a damaged airplane will definitely find the damage report interesting and absolutely not fun.
On the other hand, if you solved a hundred crosswords, solving one more may still be fun, but hardly interesting. Riding down a slide in entertainment park will be described as fun too - it may be interesting the first time, but then you're not curious about it any more, you just do it for fun. Being given unexpected presents is fun - but since you didn't expect them, you didn't have time to find that interesting.
Best Answer
WAR
-Cambridge online
Warfare
-Cambridge online
War describes a state of political affairs between 2 or more regions/countries engaging in armed conflict.
Warfare would include the strategy and tactics of the opposing forces.