Phrasal verbs are multi-verb words that form a single meaning, acting as one grammatical unit. They combine a core verb with a particle, which typically looks like a preposition but actually serves as part of the verb phrase.
turn (verb) + up (particle) = turn up – to arrive, usually without planning
I turned up at the party at 8 pm.
Combined, the verb and the particle (or particles) create a specific meaning different to the original verb.