The word 主要 is formed through the logical combination of two independent, meaningful characters (主 and 要) into a single conceptual unit. The first character, 主 (zhǔ), carries the core idea of "master", "primary", or "host", establishing a fundamental sense of primacy. This is directly combined with the second character, 要 (yào), which conveys "essential", "important", or "to want". Their union creates a coordinated compound where the meaning of "primary" (主) modifies and intensifies the sense of "essential" (要), resulting in the integrated concept of "main", "principal", or "major".