What does interference with contractual relations mean?

As the name implies, interference with contractual relations means interfering with a contract.

First and foremost, a contract has to exist. Additionally, a third party interferes with that contract and that interference is intentional and unjustified.

Also, the interfering party must have knowledge that there is a contract with which he or she is interfering. Finally, injury or damages resulting from that interference must occur in order for there to be a legal cause of action.