What is "difficulty" and how it relates to "target"? I don't understand what "difficulty" means and how it really relates to "target".

I understand what "target" is - it tells the miners, how small the resulting hash should be. (Basically, how many zeroes are there at the beginning, altough not exactly.)

But I don't understand what "difficulty" is, how it relates to the target and why it's important. I tried to read the article on wiki - https://en.bitcoin.it/wiki/Difficulty - but I don't have a clue what is it trying to say either.
Difficulty is basically a different representation of the target to make it easier for normal humans to understand it.

Difficulty represents how difficult the current target makes it to find a block, relative to how difficult it would be at the highest possible target (highest target=lowest difficulty).  The current difficulty of 6,695,826 means that at a given hash rate, it will, on average, take ~6.6 million times as long to find a valid block as it would at a difficulty of 1, or alternatively, it will take, again on average, ~6.6 million times as many hashes to find a valid block.

Difficulty is the largest possible target (0x00000000FFFF0000000000000000000000000000000000000000000000000000) divided by the current target (as of right now, 0x00000000000002816E0000000000000000000000000000000000000000000000).