Christmas celebrates the birth of Jesus, Easter celebrates the "resurrection" of Jesus.
Christians believe than Jesus "Was crucified, dead, and buried: He descended into hell; The third day he rose again from the dead; He ascended into heaven, And sitteth on the right hand of God the Father Almighty." The resurrection is his rising from the dead on the third day.
Christmas is always celebrated on December 25th, Easter is celebrated on a date that is calculated in a complicated way and reflects a lunar calendar.
Christmas can fall on any day of the week. Easter always falls on a Sunday, "Easter Sunday."
In the United States and England, Christmas is culturally rich and complicated and blends elements from many traditions besides the Christian tradition. It is a an important holiday for people of all faiths. The custom of Christmas gift-giving has grown into an important economic and commercial phenomenon.
Christmas is the most important secular holiday, If a business ever closes at all, it closes on Christmas.
To Christians, Easter is the most important religious holiday. To non-Christians, it is a pleasant but not very important time of year. Because it falls on a Sunday, it is not a work holiday.