The fundamentals are about positional elements and strategic principles.
For example: Relative value of the pieces, Control of the center, Pawn structure, Tactics, Initiative, Tempo, Opposition, Keep the position balanced, Develop multiple ideas/areas (strategy), Control open lines (files/ranks/diagonals) and crossings
For example: Relative value of the pieces, Control of the center, Pawn structure, Tactics, Initiative, Tempo, Opposition, Keep the position balanced, Develop multiple ideas/areas (strategy), Control open lines (files/ranks/diagonals) and crossings