Symmetric Multiprocessor
Symmetric Multiprocessor System (SMP). Multiprocessor system with centralized Shared-Memory called Main Memory (MM) operating under a single OS (Operating System) with two or more homogeneous processors [1].
More precisely a SMP is a tightly coupled multiprocessor system with a pool of homogeneous processors running independently, each processor executing different programs and working on different data and with capability of sharing common resources (memory, I/O device, interrupt system, etc) and connected using a system bus or a crossbar.
Usually each processor has an associated private high-speed memory know as cache memory (or cache) to speed-up the MM data access and to reduce the system bus traffic.