As i understand it,an elemental is a spirit associated with one particular element in nature(fire,air water earth etc),i don't know too much about them but i think a lot of them are supposed to be fae.
Elementals are spirits. There are elementals for every element.
Dwarfs for earth, silph for wind, undines for water and salamanders for fire. They exists as an element. The body of a dwarf is a rock(earth.), the body of an undine is water etc.
Even plants have elementals. Roses have their own soul, tigers have their own soul, etc called elemental. Even the grass has it's own elemental.
We can comunicate with them in the astral plane or through a ritual. You can also send your thoughts to them.You can't make one.
Elementals are pure spirits. They don't know the differences between good and evil. Salammanders are only interested in present, they are spirits of present, full of energy and life. Undines are very beautiful and sometimes magicians died because they wanted to be with them.(the undines didn't want that but it was the magicians choice.). They know a lot, they are very old. They are the most kindest. Silph are friendly and full of energy also. And dwarfs are very intelligent and very stable emotionally.
Fire elementals have their own god, water elementals another one, earth have their own particular god and so is for air. You can make an elemental angry(even if they don't know the difference between evil and good, they aren't stupid.)
Elementals can influene the phisical plane but also can influence emotions. The elemental of the rose is very good for finding your love,etc.
from what i've seen and was taught elementals aren't spirits but are people. At least on the outside they appear to be people but you can see and feel it inside them that they are so much more. Other than that every is the same from what you said.
Thoughtforms are very dangrous if they stay too much time.
You can create a thoughtform but then you need to destroy it before it becames to powerful.
There is a story about this. A human made a golem that helped find the culprit and also to protect the village. The golem done that, and when it was peace, the golem didn't had any order. He went into someone's garden and took a flower on it's own. The owner of the gardner yelled at him and the golem became mad and started destroying the village. He didn't listen anymore to anyone. He was barely stoped and destroyed.
That is the problem with Thoughtforms. They will develop their own personality and they will stop listening. You can create a thoughtform and assign it an order(ex. to protect). You can't banish a thoughtform and it's very hard to destroy one.
With elementals, you can banish them and they will leave you alone because they have their own place;where to go. They have a "home" to where to go. Thoughtforms don't have. They are your own energy and they will not leave you alone.
Elementals are beings of pure element, unlike beings of the physical world which are all created by an interplay of all elemental energies. As pure elemental energy, they do not exist on the physical world per se, but they are sometimes "seen" in their natural element, such as salamanders in fire, undines in water, etc.
Elementals are intelligent, although for a large part their knowledge is centered on the concerns of the elemental energy they are composed of. They are not evil but can be mischevious when not properly directed. Elementals are not created, although you can summon and direct them to specific tasks that they are suited for. Great care should be taken when doing so, as they will follow instructions to the letter, and will put their own understanding on instructions that are vague. Like anything else, when used responsibily they are a great asset.
As they are not physical entities, some means of non-sensory communication is required. The most common versions are scrying with a magic mirror or communication with the Astral body or the Body of Light.
Now, it is possible to create an artificial elemental. These are comprised of a single elemental energy and are escentially programed for a specific task. Then they return to the energy they were originated from. They have a limited intelligence and personality.
