The word 以及 is formed through the combination of two classical Chinese characters, each contributing a core meaning that merges into a single conjunctive concept. The character 以 carries a fundamental sense of "using" or "by means of", implying a tool for connection, while 及 means "to reach" or "to extend to". When fused, the literal idea of "using [this] to reach [that]" evolves abstractly into a function that links items, suggesting a sequential or additive extension from one element to another, much like "and also" or "as well as".