basically.. everyone has to pay tax on their earnings
if you pay more tax than you need to.. you get a nice cheque.. but if you dont pay enough then you have to send them money
if you earn less than $6000 a year, then you dont need to pay tax, therefore you get anything you paid during the year back
there are amounts that the tax goes up.. its like a certain % on your earnings (like from 6000-12999 is an amount, then from 13000-23999 its a bigger amount or something like that)
if you earn like 100000 then u still get the 6000 tax free.. then each amount is taxed at a different % then after like 70000 or something its just one amount..
sorry if that doesnt make sense