So you finally get that site of yours up and running, and sign up about fifty users for your services. You browse through the database entries, only to realize that most of the user information provided is incorrect, with email addresses that read "somewhere#something.com," telephone numbers that read "abgedaf," or birthdates saying that the applicant was born yesterday.
Where did you go wrong? The answer lies between the user submitting his or her registration and the data reaching the database. You neglected the important intermediate step of form validation.
Today, most sites that require user input, be it for a simple mailing list or a more complex online shopping system, use form validation to cut down on instances of erroneous data entering their system. Although there is no concrete way of identifying authentic data, form validation helps identify (to a large extent) the authenticity of the type of data entered, thus cutting down on the amount of "bad" data that gets into the database.