Developed in Constantinople, spread throughout the east of Europe over the centuries.
Most noted for the Great Schism of the 11th Cenutry.
Three primary Divine Liturgies: St John Chrysostom, St. Basil the Great, St. James.
The regular Daily and Sunday liturgy is the DL of St John; St. Basil is used for certain feasts, and St. James is used in some Byzantine Rite particular churches on certain feasts.
Communion is given by spoon, under both species, simultaneously.
Deacons are presumed in the liturgical texts; they have a role in all liturgies, and a specific duty to lead the litanies, and to wield the censor, and prompt the priest. Liturgies without a deacon are common enough, but the texts are based upon a common practice of having deacons.
Most Byzantine Particular Churches have married priests as well as celibate priests; most also have permanent deacons, and many retain the minor orders.
Byzantine Churches are divided into 3 areas: The narthex, the nave, and the sanctuary. The sanctuary is usually delineated by a floor to ceiling wall holding 3 doorways (and 4 doors), with the center doorway being a double door called the Royal Doors. This wall is decorated with many Icons, specific religious imagery, with a minimum of Christ-Pantrocrator and Mary-Theoktokos. Also common are icons of the patron of the parish, and of St. Nicholas, then the 4 gospel writers, St. Steven, the Last Supper, and the major feasts of the year. Aside from the Pantrocrator and Theotokos Icons flanking the royal doors, specifics for the rest vary somewhat by particular church.
The Nave is next; usually the people stand in the nave during the liturgies, tho in some particular churches, pews and/or chairs are permitted. Generally, there is a table, the tetrapod, in the middle, with an icon of the day, feast, or period of the church year upon it, plus a cross and candles.
Usually, there are two candlestands for people to place intention candles into; one each in front of the Pantrocrator and Theotokos icons.
The Sunday liturgical cycle begins with Vespers Saturday night, often followed by confession; Matins in the morning before liturgy, and then Divine Liturgy; sometimes there is no break between matins and liturgy, sometimes there is, again varying by particular church and even by pastor. The Sunday obligation is to assist in at least one, preferably all three.
Shortly before the start of liturgy, the celebrant prepares the gifts, a ritual called proskomedia, at a side table in the sanctuary, often called the proskomedia table. This does involve slicing the bread, called a prosphora, with a lance, and cutting small pieces for those commemorated, as well as a square large chunk called the lamb. In some particular churches 3, 5, or 7 prosphorae are prepared; others permit a single. The specific number of prosphorae may be increased if the prosphorae are small or the faithful are a great many.
There are a riot of colors used liturgically; the rubrics call for dark or light, and may indicate which particular colors are most appropriate; clerics generally wear the closest they have for the shade required. My pastor, for example, normally wears white; our deacon-candidate wears a gold dalmatic, for that is what he has. On marian feasts, the pastor wears white with blue, instead of his normal white with silver or red with gold. A former pastor would wear sky blue on marian feasts.
The liturgy in the byzantine church is usually sung in entirety, sometimes excepting the priests prayers, and usually excepting the sermon/homily. The readings are usually chanted, sometimes even multiple times in multiple languages (for Pascha and Nativity this is common, rare otherwise).
The common saying is that the liturgy is the catechism of the Byzantine Rite. The Divine Liturgy, Vespers, and Matins Propers are, in fact, an encapsulation of the theology for why that feast is celebrated. Paschal propers include literally dozens of hymns teaching the theology of salvation. The most common changeable parts are the Troparion, Kontakion, Prokeimenon, communion hymn, and Alleluia. These change in sets, even week by week, the 8 tones differ in text, and special feasts may add to or supplant the normal tones. Vespers propers vary day by day within the 8 week system. Each week has specific melodies associated with the 8 weeks; the melodies vary by particular church, tho musically, all seem to derive from hebrew liturgical singing.
Today, for example, the Ruthenian Church celebrates the Transfiguration. The festal proper replace the Troparion, the Kontakion, the alleluia, the prokeimenon, the Irmos is replaced with a glorification, the Second Entrance Hymn is replaced, as is the communion hymn… 5 pages of changes just for Divine Liturgy.
There are three major “flavors” of Byzantines: Greek, Slavic, and Syro-Byzantines. Each tradition does some things differently; further, each particular church within one may differ notably. In almost all cases, there are Orthodox and Catholic churches in almost all “national churches” and those will generally be very similar, if not nigh identical, in form. THe Melkites are Catholic Syro-Byzantines, and the Antiochian Orthodox are Orthodox Syro-Byzantines; when the Melkites came into union, a portion of the Synod did not, and later became the Antiochian Orthodox Church; prior, they were one church. The Ruthenian Pittsburgh Metropolia are Catholics and the American Carpetho-Rusyn Orthodox Diocese are Orthodox, and both are American Carpetho-Rusyn Slavic Byzantine Particular Churches; in this case, the ACROD split off from the catholics over the suppression of married priests in the US.
Each Byzantine particular church has subtle differences; to the casual observer, all they might notice is the particular cut of the vestments, the languages used, and whether or not the deacons all wear their orarion (stole) looped around their body.