• Single-processor architecture: CPU, memory hierarchy (caches, main memory, secondary memory), peripherals
• Shared-memory multiprocessors (each having own cache):
• Symmetric Multiprocessors (SMPs) with UMA (Uniform Memory Access)
• NUMA (Nonuniform Memory Access) shared-memory machines
• Distributed-Memory Multicomputers and Networks and Clusters of Workstations (NOW and COW)