Information and Communication Technologies (ICTs) have contributed to the wellbeing and progress of societies to such an extent that countless public and private dealings depend on these technologies. Through the years, the advances in ICTs have given rise to threats that make it necessary to manage the security of these technologies. Early on, cyber security was conceived as a reactive system to protect information (Information Security); however, it later evolved to assume a proactive position that identifies and manages the threats to cyberspace (Information Assurance). This ARI explores the concepts of cyberspace and cyber security, the known risks and threats, their current management in Spain and the need to develop a national cyber security system that fosters the integration of all of the public and private agents and resources, to take advantage of the opportunities offered by the new technologies and to face the challenges that they present.