Arrest means your in custody they use the word detained when they have decided not move forward with charges.
Although you did not indicate what charge you were arrested on, and how quickly you bailed out, I am a little surprised that you were not simply booked and released to begin with. But, a simple detention, rather than an arrest on your record, is something to be very grateful for, even if you did end up paying the bail premium.
Although I am an experienced CA criminal defense and appeals attorney, I can not 'guarantee' that my answer is entirely accurate, since I have not reviewed all of the factual circumstances of the case, nor have I discussed those circumstances fully with the questioner. The fact that I have answered this question does not establish an attorney client relationship between the questioner and my self or my office.