Why is Cross considered as a holy symbol by the Christians? What is meant by Resurrection of Jesus?

Jesus was sentenced to death on a Cross. From then onwards, Cross became a holy symbol for Christians as it reminds about God's love for them. It is believed to represent Jesus' victory over sin and death.

After Crucifixion, Jesus' body was removed from the cross and placed in a sealed tomb. On the third day, his disciples found the tomb empty. According to the Christian religious belief, Jesus rose again from the dead. This is called Resurrection of Jesus. It is celebrated as Easter Sunday.