Forgery is when someone creates a fake writing with the intent to defraud someone. The fake writing has to have some kind of legal significance. It's not a forgery if you write a fake letter of recommendation or resume. But it is forgery if you write a fake check. Forging checks is the most common kind of forgery.
In Virginia, the most common kind of forgery is a class 5 felony. Class 5 felonies are punishable by up to 10 years in prison. Because forgery is often a financial crime, it is unlikely that someone convicted of forgery would receive anywhere close to 10 years in prison.
Proving that someone intended to defraud someone else is usually proved by circumstantial evidence. But it can also be proved by your own statements. If the prosecution presents evidence that you told someone the check was forged, that can be used to prove you had the intent to defraud. There's also a special rule in Virginia that says being in possession of a forged writing itself is evidence that you intended to defraud.
Uttering is when you use or attempt to use a forged document. Once someone creates a forged document, the crime of forgery is completed. Even if you don't use the document, you can be convicted if the prosecutor can show that you intended to defraud someone. Once you use the forged document, you can be charged with uttering.
It is very common for someone to be charged with both forgery and uttering. It's an easy way for the prosecutor to put pressure on someone to plead guilty. The prosecutor will offer to drop the uttering charge if you plead to the forgery charge. You should make sure that you understand whether you're actually receiving much benefit from that kind of agreement.
In Virginia, the most common king of uttering is a class 5 felony. A class 5 felony is punishable by up to 10 years in prison.