The dogmas are the same, the practices are diffrent.
Orthodoxes and Catholics have similar beliefs(unlike protestants and catholics). A schism occurred in 1054, it was due to a certain number of different practices between these two churches. Catholics use Latin (or more precisely used to use Latin during masses) whereas Orthodoxes use Greek. Catholic priests are not allowed to marry and have no beard.
Catholics are not iconoclasts(unlike Protestants) nevertheless they do not use icons(which Orthodoxes deem as the real incarnation of the saint represented) to preach, pray or kiss to worship.
There are some doctrinal difference. The Catholic church believes in the infallibility of the Pope and that the Pope has authority over all the other bishops. The Orthodox church believes that no bishop is infallible and that all the bishops are equal. Part of the reason for the spilt was the attempt of the Pope to exercise authority over the Orthodox bishops. Also the doctrine of the purgatory. Catholics believe in purgatory that after salvation people must be cleansed of their sins by a time of suffering in purgatory. The Orthodox Church does not believe in purgatory and that people are saved by grace alone.