As a matter of fact, this practice came from a long-standing tradition in the Jewish faith of honoring prophets and holy people with shrines.
The first saints were martyrs, people who had given up their lives for the Faith in the persecution of Christians.
The Church chooses saints to be celebrated worldwide very carefully -- they must have a strong message for the Church as a whole.
Though canonization is infallible and irrevocable, it takes a long time and a lot of effort.
So while every person who is canonized is a saint, not every holy person has been canonized.
For hundreds of years, starting with the first martyrs of the early Church, saints were chosen by public acclaim.
Though this was a more democratic way to recognize saints, some saints' stories were distorted by legend and some never existed.
Patron saints are chosen as special protectors or guardians over areas of life.
These areas can include occupations, illnesses, churches, countries, causes -- anything that is important to us.When the pope proclaims the candidate beatified or "blessed," the person can be venerated by a particular region or group of people with whom the person holds special importance.Only after one more miracle will the pope canonize the saint (this includes martyrs as well).There are over 10,000 named saints and beati from history, the Roman Martyology and Orthodox sources, but no definitive "head count".Canonization, the process the Church uses to name a saint, has only been used since the tenth century.Since saints led holy lives and are close to God in heaven, we feel that their prayers are particularly effective.