General court litigation is split into two types – criminal and civil. The terms, rules and penalties depend on whether the wrong involved rises to the level of a crime.

With the potential loss of liberty, society demands that the highest burden of proof (beyond a reasonable doubt) be met. In civil cases, the general burden is the lesser preponderance of the evidence standard (more likely than not).
In criminal law, you have a prosecuting attorney on one side and a defense attorney on the other. In the civil context, there is still a defense attorney. But, the attorney for the party bringing the case is called the plaintiff’s counsel. In a criminal context, a defendant is found “guilty” and is “convicted” while a civil defendant is found “liable.”
While the differences can be confusing, I think it makes sense to people if they remember that American justice system reflects societies’ determination that the potential loss of liberty is much more serious than the potential loss of money or other property.