The road to dual-core processors really began when Intel and AMD discovered that the goal of improving processor efficiency and performance by increasing the clock speeds towards the 3-GHz mark and beyond was actually having the opposite effect. The faster clock speeds were producing more heat and consuming more energy, both of which were hindering the efficiency and performance of the processors. Both companies realized that they needed to move towards dual-core processor technology in order to continue to improve processor performance.
Dual-core processors contain two processor cores on one chip; consequently, they can simultaneously perform calculations on two streams of data, which increases efficiency and speed when running multiple programs. This is especially true when running new, multi-threaded software, such as video and audio editing applications.