Section "I. Definition of the Phrasal Verb and Similar Concepts" answers your question, but do read the entire page. All bolds are mine:
A phrasal verb in Present-Day English is a verb that takes a complementary particle, in other words, an adverb resembling a preposition, necessary to complete a sentence. A common example is the verb “to fix up”: “He fixed up the car.” The word “up” here is a particle, not a preposition, because “up” can move: “He fixed the car up.” This movement of the particle “up” quickly distinguishes it from the preposition “up”.
Because the forms of the particle and the preposition are themselves identical, it is easy to confuse phrasal verbs with a very similar-looking type of verb: the prepositional verb. A prepositional verb takes a complementary prepositional phrase. Movement verbs are readily identifiable examples. For example, the verb “to go” is intransitive, and without the benefit of context, it cannot operate in a complete sentence only accompanied by a subject. One cannot say, “I went,” and expect to satisfy a listener without including a prepositional phrase of place, such as “I went to the store.”
Prepositional verbs are immediately distinguishable from phrasal verbs in terms of movement, as prepositions cannot move after their objects. It is not possible to say, “I went the store to,” and so “went” is a prepositional verb. There are, in fact, several syntactic tests to distinguish phrasal from prepositional verbs, and these will be discussed in detail in the final section. It is also necessary to understand that the term “verb phrase” refers not to phrasal verbs, but more generally to a sentence verb, its complements, and matters of tense, aspect, mood, voice and so on.