Easter is the fundamental and most important festival of the Eastern and Oriental Orthodox. Every other religious festival on their calendars, including Christmas, is secondary in importance to the celebration of the Resurrection of Jesus Christ. This is reflected in the cultures of countries that are traditionally Orthodox Christian majority. Easter-connected social customs are native and rich. Christmas customs, on the other hand, are usually foreign imports, either from Germany or the USA. Eastern Rite Catholics in communion with the Pope of Rome have similar emphasis in their calendars, and many of their liturgical customs are very similar.
This is not to say that Christmas and other elements of the Christian liturgical calendar are ignored. Instead, these events are all seen as necessary but preliminary to the full climax of the Resurrection, in which all that has come before reaches fulfilment and fruition. Pascha (Easter) is the primary act that fulfils the purpose of Christ's ministry on earth—to defeat death by dying and to purify and exalt humanity by voluntarily assuming and overcoming human frailty. This is succinctly summarized by the Paschal Troparion, sung repeatedly during Pascha until the Apodosis of Pascha (which is the day before Ascension):