The temple in the Orthodox Christian tradition is called the corresponding building, consecrated in a special rite, in which Church services are conducted, including the divine Liturgy. In the Church is necessarily an altar, inside of which there is a throne. Thrones may be different. For example, portable and stationary. Importantly, the throne was enclosed the relics of Holy martyrs. It is a tribute to the ancient tradition of celebrating the Holy Liturgy on the tombs of the martyrs (relics of saints). On the throne must be kept the antimension, which is a plat depicting Christ lying in the tomb. Without the throne, and the corporal can't be celebrated the Liturgy. Thus, the main parameter in the definition of the Church is not just the size of the structures, and the presence of the consecrated altar with the corporal. If it is and the divine Liturgy all the time, the building may be called a temple. In the temple, beyond the altar, there is the Central part, where are the believers during the prayer, and can also be a porch.
The main difference between the chapel from the Church is the lack of the Holy see and of the corporal. In this building, it is possible to conduct prayer services, memorial services, burial services, perform other rites and even of worship, but not the divine Liturgy. The main service that Christians can not be done without the antimension.
Sometimes in the chapel bring a small altar with a corporal at the time to serve the Liturgy. Some chapels do it very often, so they may be called "the Church". Sometimes can also refer to small churches where services are held temporarily until it completed the construction of the main Church or Cathedral of the whole Church complex.