Valentines Day is a day to celebrate romance and love. Overtime, it has become a festival of candy and cupids. Although, it is not clear why February 14th is known as Valentine's day or if Valentine is in any way related to this day. Its history is impossible to trace.
The modern day celebration of Valentine's day started with the Christians and Romans. It was during the 5th century when it was declared as St. Valentines Day. And later on during the 14th century it became the day romance is celebrated. Their celebration before isn't even close to how we celebrate Valentine's day today.
But this shouldn't be the only day you celebrate love. You should celebrate love everyday. It does not have to be grand, even the little things will keep the love burning.