Neither label wholly suits me, so I mostly use a conflation of both for lack of a better term that might even roughly communicate what I believe in. (Maybe I should coin a new term... hmmmm....)
Pantheism (Greek: πάν ( 'pan' ) = all and θεός ( 'theos' ) = God, it literally means "God is All" and "All is God".) is the view that everything is of an all-encompassing immanent abstract God; or that the Universe, or nature, and God are equivalent. More detailed definitions tend to emphasize the idea that natural law, existence, and the Universe (the sum total of all that is, was, and shall be) is represented in the theological principle of an abstract 'god' rather than a personal, creative deity or deities of any kind.
Panentheism (from Greek πᾶν (pân) "all"; ἐν (en) "in"; and θεός (Theós) "God"; "all-in-God") is a belief system which posits that God exists and interpenetrates every part of nature, and timelessly extends beyond as well. Panentheism is distinguished from pantheism, which holds that God is synonymous with the material universe.
My personal view differs from both, insofar as I like to avoid the term "god" altogether, feeling that it carries too many misleading notions (such as picturing the deity as an entity whose psychological makeup or even physical appearance resembles our own, or as a supernatural potentate interfering with the universe by means of a celestial bureaucracy).