The whens, hows, and whys of prayer

So what exactly is prayer? How does a "Christian" pray? I know how I pray. I know what prayer is to me, but is it the same for all Christians? Do I have the right to speak for all of them? How do I describe the joy of praying in the Spirit and the feelings of being safe at home that I feel? These were my thoughts the other day when a Muslim friend asked me when do Christians pray. When I replied all the time or anytime, the follow-up question of how do you pray was not far behind. The unasked question was why do I pray. The conversation was a quick one, but thoughts and feelings from it resonant within me like church bells within a small village that search for "ears to hear".