The structure of the Orthodox Church is centered in the Bishop: this is the Local Church, the diocese. Apart from the office of bishop there is no higher ecclesial authority. There are other administrative titles associated with bishops (Metropolitans, Patriarchs), but they're all charismatically speaking "just" bishops.
Within the structure of the diocese the basic unit is the ecclesiola, the Church of the home, with the father in the role of spiritual head. Here is where the basic asketical outworking of grace takes place in the day to day activities and prayers and worship of the home. The family gathers for household prayers, the parents catechize the children, and all live the life of grace.
The ecclesiolae, then are what make up, administratively speaking, the local parish, which is served by a priest on behalf of the bishop and deacons, subdeacons, readers and acolytes, as well as all the laypersons. The parish is the locus of where the Mysteries (Sacraments) are administered and through the Eucharistic Mystery the Local Church (diocese) is constituted via the life of the parish.
I hope that helps.