Energetic neutral atoms (ENAs) are a key component of the space environment and play a crucial role in various astrophysical and planetary processes. ENAs are created when solar wind ions interact with neutral atoms in the interstellar medium, planetary atmospheres, or other space environments, resulting in charge exchange reactions that produce high-energy neutral particles. These ENAs can provide valuable information about the composition, dynamics, and interactions of plasma and neutral gas in various space environments, including planetary magnetospheres, comet comas, and the interstellar medium. They can also be used as a diagnostic tool to study the energy distribution and origin of charged particles in space. Research on ENAs involves the development of instrumentation and techniques for detecting and analyzing these particles, as well as theoretical studies to understand their formation and interaction processes. By studying ENAs, scientists can gain insights into the complex processes occurring in space environments and improve our understanding of the physical mechanisms governing the behavior of plasma and neutral gas in the universe.