IANAL, but arrest, by definition, means to take into custody. Technically, arrest includes the right to transport someone, and some laws in some jurisdictions g

IANAL, but arrest, by definition, means to take into custody. Technically, arrest includes the right to transport someone, and some laws in some jurisdictions grant powers to detain but not arrest (usually in association with search warrants or traffic laws). In most legal jurisdictions, police can question you without arresting you -- but if you aren't under arrest, you are free to leave at any time. There is not usually any legal limit on how long such questioning can last -- it is a meeting between two consenting legal entities (you and the police) and either party is free to stop the questioning and leave. In some cases, your answers to the questions under this situation could bring you under reasonable suspicion and be grounds for arrest -- and a lawyer could help with that. If you are being 'held' (meaning you aren't free to leave), then you are under arrest, essentially by definition. I believe many civil liberties organisations explicitly asking something like 'am I free to leave?', forcing police to either acknowledge that you aren't under arrest and may leave if you wish, or commit to legally acknowledging you are under arrest, requiring them to justify it in court if you sue them.