To me there is a difference between prayer and contemplation. They are not the same.
In general, prayer is a supplication, a requesting, an honouring, a thanking. In other words, it’s an expression of some feeling or emotion. Usually, it is very specific in its orientation, wanting help or what have you. Often, it involves words or some other medium of expression. There is usually a strong sense of self. It’s me and god.
Contemplation, on the other hand, is a change in a state of mind. It is an altered consciousness. Often, there is no expression of a feeling or emotion. It seldom entails anything specific or has a single intention in mind. Usually, there are no words or any other medium of expression. The sense of self is not prevalent in contemplation. Usually, contemplation requires a destruction or loss of self.
There are times when one passes from one to the other and vice versa. There are times when they are so alike that you can’t tell the difference. But, overall, they are like opposites and having opposite traits. Because they are opposite they compliment each other and make each other relevent, much like night and day. As a result of this, both are needed.