In its simplest terms prayer is talking to God. There are many different kinds of prayer , and though this is by no means a treatise on the subject, I will touch on a couple types of prayer for my purposes here: Intercession and Personal Petition.
Thank you many times over for your prayers of faith for me, and Randy. Please don’t give up! (from my blog http://jacquesjourney.blogspot.com/)
Intercessory prayer is praying for another person or group of people. It is coming to God on behalf of another. Jesus, as our Great High Priest in heaven, has this ministry to us now, standing before our heavenly Father, speaking on our behalf, advocating for us (I Timothy 2:5; Hebrews 4:14, 15; 7: 24, 25). He is our perfect Advocate, like the very best courtroom lawyer. He lived here as a human and understands us perfectly, and because He always pleads for us according to God’s will, He is always heard.
The Spirit of God, who lives in those of us who trust Jesus for salvation, intercedes for us as well with groans that cannot be put into words (Romans 8:26). And of course, His intercession for us is done perfectly and according to the will of God because the Spirit of God knows what the will of God is (Romans 8:27).
So we, too, are told to intercede for others, praying to God on their behalf (I Timothy 2: 1-4; Ephesians 6:18, 19). In my mind I picture intercession this way: When I intercede for a friend I step between my friend and God and plead her cause, like a trial lawyer would do for his client before the judge. Of course, because my understanding is finite I must seek out the mind and will of God in the whole process. God’s knowledge is infinite; He knows what is best for my friend. Since my knowledge is limited I would just be guessing unless I ask the Lord for insight in how to pray for the very best outcome for my friend. Even in my uncertainty of how to pray for my friend, as I continue to seek His mind, I have the certainty that God will answer according to His will, for my friend’s good and His glory.
 An excellent book on types of prayer is Richard J. Foster’s Prayer: finding the heart’s true home (San Francisco: HarperSanFrancisco, 1992)
 Hebrews 5:7-10; 4:14-16