Cache memory in CPU architecture is organized in a hierarchical structure, typically comprising Level 1 (L1), Level 2 (L2), and Level 3 (L3) caches.

Cache memory is a type of high-speed, volatile computer memory that supplies the processor with the most frequently accessed data and instructions. It is smaller and faster than main memory and is situated closer to the processor core, facilitating quicker data exchange. This hierarchical organization of cache memory ensures efficient data retrieval, enhancing overall system performance.

The L1 cache is the smallest and fastest of the caches, located directly within the processor chip. It is divided into two sections: one dedicated to data (known as the L1d cache) and the other for instructions (referred to as the L1i cache). The L1 cache temporarily stores instructions that are pending execution and immediate data required for processing.

The L2 cache is larger and slightly slower than the L1 cache. Like the L1 cache, it is also situated within the processor chip and serves as an intermediary between the small, rapid L1 cache and the larger, slower main memory. The L2 cache holds data and instructions that are not immediately needed by the processor but are likely to be required in the near future.

The L3 cache is even larger and slower than the L2 cache. It is located outside the processor chip on the motherboard, yet it remains significantly faster than main memory. The role of the L3 cache is to act as a supplementary resource for the L1 and L2 caches, storing data and instructions that are less likely to be needed imminently.

In some systems, a Level 4 (L4) cache may also be present, positioned even further from the processor, although this configuration is less common. The hierarchical organization of cache memory is designed to provide the processor with the most frequently needed data and instructions as swiftly as possible, thereby enhancing the overall performance of the computer system.