What is l2 cache and l3 cache?

Each one is larger, cheaper and slower than the next. L1 cache tends to be direct mapped and L2 tends to have higher associativity. I don't believe that any current processors use L3 cache yet, but...

Each one is larger, cheaper and slower than the next. L1 cache tends to be direct mapped and L2 tends to have higher associativity. I don't believe that any current processors use L3 cache yet, but...

Not the same.

L2 cache is a set of memory circuits designed to speed access to important and frequently used data. L2 cache is an abbreviation of Level 2 cache.

Larger the size is better but it is hard to know how much better. Read/Write latency (time) is also an important factor for performance.