In the Christian tradition, there is a teaching about special church sacraments, during which divine grace descends on a person. In Orthodoxy, there are seven sacraments, one of which is the Eucharist.
The Eucharist is one of the sacraments of the Church, during which the real essence of the Body and Blood of Christ the Savior is miraculously applied to the essence of bread and wine. This miracle occurs during the Eucharistic Canon when the priest invokes the Holy Spirit on the prepared gifts.
The Eucharist is the centerpiece of the divine liturgy. This sacrament was established by Jesus Christ Himself during the Last Supper. The Savior himself commanded to celebrate the Eucharist in remembrance of Him. If we turn directly to the Gospel, then we can read about the need for a believer to approach the sacrament of the Eucharist (communion). Thus, the Savior said that those who do not partake will not have life in themselves, because it is he who eats the Body of Christ and drinks His blood that has eternal life.
In Orthodoxy, a clear concept is given that in the Eucharist (or the communion of believers) there are the real Body and Blood of Christ Himself. Therefore, the one who partakes not only and not simply divine grace, but the Lord Himself, uniting with Him. It is also worth noting that the Orthodox receive communion under two types - that is, Body and Blood. For Catholics, communion takes place under one guise - only by the Body.
It is also necessary to point out that the communion for Protestants is not a great sacred rite, but just a custom, a memory of the historical event of the Savior's celebration of the Last Supper. Therefore, Protestants have no idea about the real presence of the essence of the Body and Blood of Christ in bread and wine.