Plants communicate with insects and other organisms through the release of volatile organic compounds (VOCs). Using Boolean operators, we retrieved 1093 articles from the Web of Science and Scopus databases, selecting 406 for detailed analysis, with approximately 50% focusing on herbivore-induced plant volatiles (HIPVs). This review examines the roles of VOCs in direct and indirect plant defense mechanisms and their influence on complex communication networks within ecosystems. Our research reveals significant functions of VOCs in four principal areas: activating insect antennae, attracting adult insects, attracting female insects, and attracting natural enemies. Terpenoids like α-pinene and β-myrcene significantly alter pest behavior by attracting natural enemies. β-ocimene and β-caryophyllene are crucial in regulating aboveground and belowground interactions. We emphasize the potential applications of VOCs in agriculture for developing novel pest control strategies and enhancing crop resilience. Additionally, we identify research gaps and propose new directions, stressing the importance of comparative studies across ecosystems and long-term observational research to better understand VOCs dynamics. In conclusion, we provide insights into the multifunctionality of VOCs in natural ecosystems, their potential for future research and applications, and their role in advancing sustainable agricultural and ecological practices, contributing to a deeper understanding of their mechanisms and ecological functions.