An indictment is pre-trial. To get a criminal indictment, all you need to show to a grand jury is "probable cause," which is a very low standard--the same standard needed to justify an arrest. That's the reason for the old joke about being able to indict a ham sandwich.

Now that Comey's been indicted, the trial process will begin, assuming he doesn't plea out (and I don't think he will). The uphill battle for the prosecution now begins.