From “The Complete Artscroll Siddur.”
The Hebrew name is תְּפִלָּה, teffillah, a word that gives us an insight into the Torah’s concept of prayer. The root word of tefillah is פלל, to judge, to differentiate, to clarify, to decide. In life, we constantly sort out evidence from rumor, valid opinions from wild speculations, fact from fancy. The exercise of such judgments is called פלילה. Indeed the word פליליס(from פלל) is used for a court of law (Exodus 21:22), and what is the function of a court if not to sift through evidence and make a decision? A logical extension of פלל is the related root פלה, meaning a clear separation between two things. Thus, prayer is the souls yearning to define what truly matters and to ignore the trivialities that often masquerade as essential (Siddur Avodas HaLev).
People always question the need for prayer – does not G-d know our requirements without being reminded? Of course He does, He knows them better than we do. If prayer were intended only to inform G-d of our desires and deficiencies, it would be unnecessary. Its true purpose is to raise the level of the supplicants by helping then develop true perceptions of life so that they can become worthy of His blessing.
This is the function of the evaluating, decision-making process of תְּפִלָּה, prayer. The Hebrew word for praying, מתפלל; it is a reflexive word, meaning that the subject acts upon himself: Prayer is a process of self-evaluation, self-judgment; a process of removing oneself from the tumult of life to a little corner of truth and refastening the bonds that tie one to the purpose of life.