What is the difference between fraud and abuse?

What is the difference between fraud and abuse?
Fraud occurs by individuals to many people that are engaged as a group that work in secret to defraud the organization. When we consider the groups involved in fraud we can see how organized crime has infiltrated the Medicare Program and represented themselves as Medicare providers and suppliers. Health care fraud can also happen at the individual level. Consider the following scenario and answer the discussion prompts below.
Instructions:
While working at the medical office where you are a reimbursement specialist, you notice that a Medicare patient has many more laboratory tests done than a non-Medicare patient.
Could this be a case of fraud or abuse? Why or why not?
Is it appropriate to notify your office manager?
How will you safeguard yourself from getting involved in this type of crime especially if everyone is doing it and it proves highly lucrative?