Intel’s dual core processors were simply 2 Pentium 3 processors that were fabricated in a single chip. Initially, Intel called their dual core processors as Core Duo, a very obvious reference to two cores, while AMD called theirs the X2. All processors that have 2 cores in them are collectively called as dual core processors regardless of which manufacturer it came from, while those that have 4 processors in a single chip are called quad core. Two or more cores can greatly aid in multi-tasking where each core can work independently of each other. Because the number of transistors in a single chip continues to follow its upward trend, processor manufacturers like Intel and AMD have decided to go a different route in increasing the performance of their products, adding more cores into a single chip that leads to a performance boost if the OS supports it.
The processor wars have hit a major speed bump as clock speeds become harder and harder to push upwards. Dual core processors are those that contain 2 cores in a single silicon chip while Core 2 Duo is the name given by Intel to its second batch of dual core processors.
