Level 1 Primary Cache- L1 is the primary cache memory, it is very fast cache memory. The size of this memory is less as compared to other memory.
Level 2 Secondary Cache- L2 is the secondary cache memory. If you compare the Cache Size of L2 with L1 Cache Size, then the size of L2 Cache is bigger than L1. The size of L2 varies from about 256 KB to 512 KB.
Level 3 Main Memory- The size of the cache of L3 memory is more than both L1 and L2. But the speed of L3 memory is much less than L1 and L2.