In consumer technologies, multi-core is usually the term used to describe two or more CPUs working together on the same chip. Also called multicore technology, it is a type of architecture where a single physical processor contains the core logic of two or more processors. These processors are packaged into a single integrated circuit (IC). These single integrated circuits are called a die. Multi-core can also refer to multiple dies packaged together. Multi-core enables the system to perform more tasks with a greater overall system performance. Multi-core technology can be used in desktops, mobile PCs, servers and workstations. Contrast with dual-core, a single chip containing two separate processors (execution cores) in the same IC.
See “All About Dual-Core Processors” in the “Did You Know…?” section of Webopedia.