Best share is the highest difficulty share you have found.

The block difficulty is the minimum difficulty required for solving the block.

If your best share's difficulty is higher than the block difficulty, it means that you have found at least one block. Otherwise, all of your shares were not enough to solve a block.

In terms of your income, unless your pool rewards block finders more than others (which is very rarely the case), it does not matter to you at all.

Also, yes, 10 mil. will be "closer" to solving the block than 1 mil., but you either solve a block or you don't. So "closer" doesn't mean anything.