Fraud is simply deception for unlawful gain. The biggest challenge is the interpret what is lawful / unlawful.
In law, fraud is intentional deception to secure unfair or unlawful gain, or to deprive a victim of a legal right. Fraud can violate civil law (i.e., a fraud victim may sue the fraud perpetrator to avoid the fraud or recover monetary compensation), a criminal law (i.e., a fraud perpetrator may be prosecuted and imprisoned by governmental authorities), or it may cause no loss of money, property or legal right but still be an element of another civil or criminal wrong. The purpose of fraud may be monetary gain or other benefits, for example by obtaining a passport, travel document, or driver's license, or mortgage fraud, where the perpetrator may attempt to qualify for a mortgage by way of false statements.