The were as regular as clockwork, pulsing once every second. The signal was originally thought to be coming from an orbiting satellite, but that idea was quickly disproved. After several more of these objects had been found, they were names pulsars because of their rapidly pulsing nature. Bright pulsars have been observed at almost every wavelength of light. Some can actually be seen in visible light.
Many people tend to get pulsars confused with quasars.
But the two objects are totally different. Quasars are objects that produce enormous amounts of energy and may be the result of a massive black hole at the center of a young galaxy. But a pulsar is a different animal entirely. A pulsar is basically a rapidly spinning neutron star. A neutron star is the highly compacted core of a dead star, left behind in a supernova explosion.