Cache hierarchies

Cache hierarchy refers to the layered system of small, fast storage units inside a computer, designed to quickly provide data to the processor. Typically, there are multiple levels—L1, L2, and L3—where L1 is the smallest and fastest, closest to the core, while L3 is larger but slower. Data that the processor needs is first looked for in L1, then L2 if not found, and finally in L3 if still missing. This hierarchy minimizes delays, improving overall speed by keeping frequently used data close to the processor and reducing time spent accessing slower main memory.