Endophytic microorganisms are secretive partners of plants that coexist with them inside their hosts. Endophytes have been recognized for the past century, despite the fact that they are thought to have evolved and been related with land plants. Over the past ten years, a plethora of research have demonstrated the critical role that plant microbiomes play in the resilience, growth, and development of a wide range of plants, including species that are commercially significant. Due to their ability to synthesize a wide range of chemicals and interact with both pathogenic and non-pathogenic microorganisms, endophytes have become more relevant due to their potential to yield novel compounds with therapeutic significance and to increase agricultural productivity. It is now feasible to correctly identify these microorganisms and learn about their interactions with their hosts and other microorganisms thanks to the advancement of contemporary molecular biology tools and procedures. In this summary, the volume emphasizes how our knowledge of endophytic plant growth-promoting bacteria can help us make better use of them to raise crop output and quality.