I don’t know the “Protestants' understanding” on praying, but the Orthodox understanding is that prayer is private, and its purpose is to have communion with God so that we are capable of accomplishing his will. I think that there are four types of prayer: asking, thanking, praising, and questioning God.
The Orthodox understanding is that “Worship” is not private prayer; in the Church services, we pray with others, together as one body in the unity of one mind, one heart and one soul. (We can unite our concerns to Church, but it is a community that is praying).
Both private pray and public worship are essential to Orthodox life.