What is Abacus? Abacus is an ancient calculating device having its roots in Asia since ages. Abacus in today's times time is made of wood, metal or plastic rectangular frame with freely sliding 5 beads over vertical rods.
A health maintenance organization (HMO) and a preferred provider organization (PPO) have several differences such as which doctors patients can see, how much services cost, and how medical records are kept.The most significant difference between the two organizations is the option to select health care providers.n HMO requires that patients see only doctors or hospitals on their list of providers. With a PPO, patients can see any doctor they wish, usually within a preferred network of providers.
Advantages and disadvantages of PPO insurance. As a member of a PPO, health care costs are low when the member stays within the provided network. This plan allows more freedom than an HMO in many ways.