The circumgalactic medium (CGM), the gaseous halo enveloping galaxies, plays a crucial role in shaping the evolution of galaxies by providing the fuel for star formation. This medium is multiphase and exhibits a vast temperature structure, ranging from the cool 10^4 K gas to super-virial 10^7 K gas. The presence of the cool gas in the outer CGM presents intriguing questions, as does the enigmatic location of the newly discovered super-virial gas. In this talk, I aim to shed light on these two enigmas by leveraging simulations and observational studies.