The value of the z-score tells you how many standard deviations you are away from the mean.
A positive z-score indicates the raw score is higher than the mean average and if its equal to 0, it is on the mean.
Formula to calculate z-score.
Suppose the mean of your sample is 5, if the standard deviation is 12, calculate how far 6 is from the mean.
Therefore, 6 is 0.14 above the mean.