Easter Sunday, which falls on April 20, is the day when Christians the world over celebrate the end of a somber Lenten season with feasts and celebration.

Easter marks the end of a 40-day period leading up to Easter Sunday that is a time of penance and reflection, which represents the time Jesus spent time alone in the wilderness before beginning his ministry, according to History.com. Christians believe it was a time during which he survived temptations by the devil.

Easter also marks the end of Holy Week, which includes Maundy Thursday, which commemorates Jesus' last supper, Good Friday, which commemorates his crucifixion, and Holy Saturday, which honors the time Jesus spent time in his tomb before his resurrection.

Easter is the time when Christians celebrate the resurrection of Jesus Christ, which is when they believe he ascended into heaven.

The origins of Easter are unknown. Some believe the name Easter is derived from Eostre, a Pagan goddess of spring and fertility. Others believe Easter is traced to the Latin term hebdomada alba, or white week, an ancient reference to week of Easter during which people wore white clothing to be baptized.

Due to a translation error, the term later appeared as esotarum in Old High German, which became Easter in English.

In most Roman Catholic, Eastern Orthodox and Protestant religious celebrations, there are baptisms, the Eucharist, feasting and greetings of "Christ is risen!"

In Roman Catholicism, Easter is celebrated with a vigil that includes baptisms, the lighting of the paschal candle and the mass of Easter.

In Orthodox churches, the vigil service is preceded by a procession outside the church. They symbolically search for Christ's body, then announce that Christ has risen. When they return to church, hundreds of lamps and candles are lit to symbolize Christ's resurrection.

Easter also has many commercial traditions, including Easter eggs, Easter baskets and candies.

Easter eggs come from the springtime fertility traditions of the pagan religion in Europe and the Middle East. Easter eggs, as well as rabbits, are both used for symbols of springtime and fertility during the Easter holiday. A common custom is for adults to hide brightly colored easter eggs for children to find.