What Solver does CFX use?

Could you please explain to me the solver that CFX employs? I'm particularly interested in understanding the technical details behind its operation. Could you elaborate on its characteristics, advantages, and any potential limitations it might have? Additionally, how does this solver contribute to the overall performance and accuracy of CFX simulations? I'm keen to gain a deeper understanding of this aspect of CFX and how it affects the results obtained from simulations. Thank you for your assistance in clarifying this matter.