The discovery process allows each side the opportunity to collect its evidence in order to prove its case should the matter proceeds to a trial. Each state has its own discovery rules but most include the right for either party to serve written questions on the opposing side. These questions are called interrogatories and they must be answered in written form and under penalty of perjury usually within thirty days of having been served upon you. In addition, both sides will be allowed to obtain the sworn testimony of the other side through the deposition process. Documents can also be subpoenaed from you or from a third party such as an escrow company.
Depending on how successful you have been in collecting as much favorable evidence as possible, you will soon get the chance to make your legal arguments and present your evidence at trial.