Differences in Eucharist Between Orthodoxy and Catholicism

1. 

Orthodox: use leavened ("real") bread

Catholic: use unleavened "bread" (host)

2. 

Orthodox: use spoon to give both body and blood of Christ to communicant

Catholic: use hand for host and chalice for wine

3. 

Orthodox: Communion is received directly in the mouth by the communicant

Catholic: Communion host can be received either on the tongue or in the hand; communion wine is sipped from chalice

4. 

Orthodox: Priest offers Communion

Catholic: Priest or Eucharistic Minister offers Communion

5. 

Orthodox: all Orthodox who have properly prepared (confession, fasting, hearing that day's Gospel, etc.) can receive Communion, regardless of age

Catholic: Eastern Rites, same as above, but Latin Rite (majority of Catholics), only receive Communion after a certain age/grade and time of "education/preparation"

6. 

Orthodox: Eucharist is not displayed or otherwise housed in a tabernacle for adoration. It is only processed around the narthex during Divine Liturgy prior to reception of Communion.

Catholic: Eucharist (consecrated hosts) is kept in a tabernacle and taken out in a monstrance for benediction/adoration/procession.  Often a church will have a tabernacle in both the narthex and the adoration chapel.  When passing in front of the tabernacle, one is supposed to reverence it.

7. 

Orthodox: Eucharistic miracles are much less common and when they do occur, seem to be a form of punishment for disbelief.

Catholic: Eucharistic miracles are much more common.

8. 

Orthodox: all communicants always receive both forms of the Eucharist.

Catholic: most of the time, only the host is received by the faithful.

9. 

Orthodox: Communicants stand, stoop down if needed, or are held (if small children) to receive the Eucharist.

Catholic: used to receive while kneeling at the altar railing, which only happens at Traditional Latin Masses now.  Otherwise, communicants generally receive while standing in line, or can genuflect before receiving or kneel on the floor (very uncommon).

10.

Orthodox: there is very little chance of desecrating the morsels of Communion.

Catholic: desecration of the host is very possible, as people receive on the hand, often walk away before putting host in their own mouth, and so could technically never actually put it in their mouth and do who knows what with it.