This chapter discusses the neural mechanisms of voluntary movements in the motor cortex - a major node in the brain network of initiation and control of such movements. Specifically, it discusses the neural mechanisms of reaching movements in space with respect to the encoding of movement parameters in the activity of single cells and the decoding of information from neuronal populations. This decoding scheme can be used to monitor the processing of movement-related information in various contexts and, ultimately, to drive motor prostheses.