Visual servoing consists in using the data provided by a vision sensorfor controlling the motions of a dynamic system, robots typically. The classical approach is based on an image processing-then-controlloop, extracting and tracking from the image a set of geometrical features used as input of a closed-loop control scheme. A more recent approach avoids this feature extraction step.The talk will present the main basic modeling and control aspects of these two approaches, as well as their respective advantages and drawbacks. An overview of the visual servoing applications in robotics will be also given.