Concept
It could be defined as an abstract idea or mental image which corresponds to some distinct entity or class of entities.
In the simplest terms, a concept is a name or label that regards or treats an abstraction as if it had concrete or material existence, such as a person, a place, or a thing.
They are understood to be the fundamental building blocks behind principles, thoughts, and beliefs.
Those are some of the definitions of the word; Concept.
In the Cosmos, the definition of a 'Concept', was not far off from these.
'Concept' was simply the label that was given to the fundamental building blocks behind the major principles of the cosmos.
An example would be the concept of fire.
If this concept did not exist, there would be no fire in the cosmos. It was as simple to understand as that.