Level 1 (L1) cache is integrated on the processor die itself and stores instructions for the processor. On multi-core systems, each processor typically has its ownL1 cache. Some processors might have two L1 caches, one for instructions and one for data.
Level 2 (L2) cache is additional cache used for both instructions and data.
Depending on the processor, L2 cache might be shared between two or more cores, or exclusive to a single core.
Level 3 (L3) cache is additional cache beyond the level 2 cache. For multi-core systems, L3 cache is shared between all cores.