This NATO AS! was the third in the series of Advanced Study Institutes on neutron stars, which started with 'Timing Neutron Stars', held in Qe me near izmir, Turkey (April 1988), followed by 'Neutron Stars, an Interdis- ciplinary Subject', held in Agia Pelagia on the island of Crete (September 1990). The first school centered on our main observational access to neu- tron stars, i. e. the timing of radio pulsars and accretion powered neutron stars, and on what timing of neutron stars teaches us of their structure and environment. The second school had as its theme the interplay between diverse...