One major advantage of an electrohydraulic system over a conventional hydraulic system is its ability to implement automatic controls. This chapter provides some fundamentals of automatic control in general and identifies three specific control functions—velocity, position, and force controls—in electrohydraulic systems. A few basic control methods used in many electrohydraulic systems are also briefly introduced. This chapter should give hydraulic system engineers sufficient knowledge to communicate with control system engineers in a professional manner when designing electrohydraulic control systems.