Depends on the structure of the business, but generally you will receive a reasonable but low-ish salary, and the rest of your income will in the form of distributions from corporate profits, which have a favorable tax rate (for now). Your share of the distributions depends on what % of the shares of the corporation you own, and likely your % of the billings.
Other advantages would be shared call, easier vacation scheduling, continuity of care for patients, more availability of appointments, greater efficiency of the practice.
Since our practice uses 3 docs to cover two FT physician slots, and there are always two docs working, we're as close to 100% efficient as possible.