what do you mean by "the discovery"? (argentinian lawyer over here)

"Turn over all relevant documents to this case so we can dig through it and discover whether you were plotting to do crimes in email," would be one example, I think?

In civil litigation here each side has the right to require that the other give them copies of documents that are relevant to the case, or which are reasonably likely to lead to the discovery of admissible evidence. That, in turn, requires that the lawyers review huge quantities of documents.