When you ask the question, "What is prayer?", you will get many different answers because there are innumerable forms of prayer in the world. Prayer is an integral part of the major religions of Islam, Judaism, and Christianity. Buddhists pray, Hindus pray, Native Americans pray, and even people in the most remote and isolated places pray. Prayer is a global phenomenon where the overwhelming majority of people will pray at some point in their lives. One study even found that 30 percent of atheists admitted that they prayed!
Of course, we shouldn't be surprised by the universality of prayer because the Biblical point of view is that all humans are made in the "image of God" (Genesis 1:26-27). Since we bear God's image, we are designed to reflect and relate to God. Because of this, every human, regardless of religion or culture, has some knowledge of God. It's embedded in our DNA to look to a greater power for help.
However, Christians believe that because of Scripture and the power of the Holy Spirit, we get a very different view of God. We believe that we are not God's subjects, but rather, we are His children! And as His children, we can talk with Him as our Father. So, OUR prayers are a personal conversation with God that give us a clearer understanding of who He is. And the better our understanding of who God is, the better our prayers.
Taking that a step further, since Jesus is the Word of God (John 1:1-14), when we pray "in Jesus' name", an even more comprehensive, personal, and beautiful communication with God is possible! Praise the Lord! This is great stuff!