In recent years, climate change and nationally determined contribution (NDC) policies worldwide have accelerated the transition from fossil energy sources to renewable energy. Consequently, the energy storage system (ESS) sector has emerged as an area of increasing importance in this industry. In particular, compressed air energy storage (CAES), which has a long history of commercialization, is reappraised as a competitive ESS technology with the potential for long-duration and utility-scale storage. The second part of the comprehensive overview aims to provide valuable insights into the planning, design, and construction stages of the CAES system. It describes various geological storage methods for CAES, such as rock salt, aquifers, and depleted gas fields, as well as the potential issues that need to be addressed when deploying each method. Furthermore, it elucidated the isochoric and isobaric storage types and introduced an analytical model for calculating the storage energy density of CAES based on each storage type with sample configurations.