My understanding of prayer is pretty much limited to the idea of praying to someone/something that has power to intervene and grant something to someone. In this sense it is similar to talking. However, somewhere along the line I heard someone refer to another way to pray, which is to listen.
This latter version seems to have more validity, and doesn't require any supernatural or imaginary entity to listen to. It's basically a form of meditation: getting quiet and listening to whatever comes up.
Per Lucretius 5:11203+/_: True piety is for a man to have the power To contemplate the world with quiet mind.