A saint is a person who is very important to a religion, especially the Christian religion. They are very good people who have done many good things in their life, and they are recognized by the church for their holiness.
When someone is declared a saint by the church, it means that they are believed to be in heaven, close to God, and that others can ask them to pray for them. It is kind of like having a special friend in heaven who you can talk to and ask for help.
To become a saint, someone must have led a very good and holy life, and they must have done many good things for others. The church investigates the person's life and determines if they are worthy of being declared a saint.
Saints are often associated with certain things, like St. Francis of Assisi is known for his love of animals and nature, and St. Nicholas is known for being kind to children. People often pray to saints for help with specific things, like St. Anthony for help finding lost things or St. Jude for help in hopeless situations.
Overall, saints are very important people in the Christian religion who are believed to be close to God and can help people with their prayers.