Attributes are the laws that govern this world, and there are eight in total.
There are the natural attributes of earth, water, fire, and wind, and the attribute of space. These are the so-called five major attributes.
Fire is stronger than earth, water is stronger than fire, wind is stronger than water, air is stronger than wind, and earth is stronger than air.
The earth is consumed by fire, fire is extinguished by water, water is dissipated by wind, wind is isolated by space, and space is indexed only by the earth. Such is the reason why the five major attributes are in a relationship of conflict.
In addition to these five attributes, there are two opposing attributes, "light" and "darkness," and the attribute of "time," which is not bound by anything, is said to reign over all attributes. It is said that the "Time" attribute, which is not held by anything, reigns over all attributes.
Spirits like the Flaming Giant are also bound by these physical laws. Or rather, spirits are the embodiment of the laws of this world, and they seem to have eight attributes.
Light" and "darkness" are special, and it seems that light is derived from angels and darkness from demons. It seems that the angelic and demonic tribes that have been confirmed now can also be called spirits if we trace them back to their roots.
I guess if you ask Diablo or someone like him, he might be able to tell you more about them, but I'm not particularly interested in learning about them.