Prayer has many purposes and numerous definitions depending on your affiliation or religious preference. For some it is a petition, asking God for something or making a request, usually in a moment of need. For some it is a religious observance or ritual using a specially word formulation such as a benediction. For some it is an act of praise and adoration where one gives glory to God or thanksgiving for what he has done. For others it is an act of contrition, repentance, or the seeking of forgiveness. Then there are those for whom it is simply talking to God as an act of personal communication. For most it is the grace or blessing before a meal.
It is all of those things and more. But one very important thing it is, is grounding. It keeps us grounded in our spiritual relationship with God. In a very important way, prayer connects us. When we let it slide, we begin to lose something very important; we can feel the distance growing between us and our heavenly Father. One could say prayer is our spiritual lifeblood; it nourishes our soul. As such it cannot be neglected for long before you begin to feel the deleterious results. Your soul starves without it.
I guess this is a roundabout way of saying for you to take your pick today of any of the forms or reasons or meanings of prayer and just do it. That is the important thing; that you do it. You need it in more ways than you can count. You know this is true.