Hi guys. So I see in my mining stat in the ck pool, there's

lastshare —> last share high of difficulty what you have send

shares —> the number of valid shares what you have send to the pool

bestshares —> best share diff sinze the last block found

bestever —> best share diff what you have ever found under this address

Some of it is self explanatory but what is the difference between say lastshares vs. shares?