Numerology is a part of mysticism that uses numbers & mathematics to determine a person's life path and their goal in life. Numerology isn't really about predicting the future, but showing the destination of a person who might be lost in life. Numerology relies on your date of birth, through which it can extract certain information about you as in life path, karmic number, soul urge, personality number etc... Numerology also tells you a lot of information from your birth name, as your first and last name have a vibration of their own.
I.e. A-1, B-2, C-3, D-4, E-5, F-6 etc... and after the 9th alphabet it starts from 1 again.
The most widely known method of numerology is the life path number. Life path number in numerology is simply the accumulation of your entire birthday numbers in to one single digit unless they end in 11,22,33, or 44, in that case they become master numbers and you never reduce a master number.
I.e. June 10th 1984: You add June which is month number 6 + 10 + 1984 = 2000, then you reduce 2000 to a single digit. In this case, 2+0+0+0 = 2. This mean the life path of this person is 2. Now, if there birthday was 6--19-1984 then you will end up with a master number in numerology. 6+19+1984 = 2009. 2+0+0+9 = 11. Sine 11 is considered a master number you do not reduce it to a single digit by adding 1 + 1. Even though master number has a lot of vibration of number 2, it still is a number in itself, and 11 has quite a different meaning than 2.
Another method of Numerology that is important is birthday number. Birthday number is simply the day you were born from 1-31st of any month. Again, if you're born on the 11th or 22nd of any month then you do not reduce that, that is your birth number since it is a master number; otherwise if you are born after the 9th day then you add those numbers.
i.e. If you're born on the 14th then you would add 1+4 = 5. Your birth number 5 or your 'Karmic Number' is 5'. Karmic number in my study is more important than life path, because Karmic number is a vibration that you experience everyday, and life path is your ultimate destination which is lead by the Karmic number train.