The primary purpose of discovery is for parties to exchange information and evidence before trial, ensuring fairness and preventing "trial by ambush" by requiring both sides to have access to relevant facts and witnesses.

The three key elements are relevance to a party's claim or defense, non-privileged matter, and proportionality to the needs of the case; proportionality involves balancing factors like the importance of issues, the amount in controversy, access to facts, and the burden of discovery.

Discoverable information is any non-privileged matter relevant and proportional to the case, while admissible evidence is information that meets the rules of evidence for presentation at trial; for example, hearsay might be discoverable if it could lead to admissible evidence.

Attorney-client privilege protects confidential communications between a lawyer and client made for the purpose of legal advice, while the work product doctrine safeguards materials prepared in anticipation of litigation; these protect the attorney-client relationship and the lawyer's preparation from adversarial scrutiny.

Two primary functions are to help each party prepare for discovery by providing a roadmap of key information and to set the stage for potential settlement negotiations by outlining case strengths and weaknesses; an example of required disclosure is the names and contact information of individuals likely to have discoverable information.

Expert witness disclosures must include the identity and qualifications of the expert, a summary of their opinions and their factual basis, and any prior testimony; failure to adequately disclose can lead to the exclusion of the expert's testimony at trial.

A deposition is a pretrial examination conducted under oath to ask detailed questions of witnesses or parties, while a request for production of documents compels the opposing party to produce relevant documents, electronic files, or tangible items; depositions primarily seek testimonial evidence, while requests for production seek documentary or physical evidence.

A party might file a motion to compel if the opposing party fails to respond to discovery requests or provides incomplete or evasive answers; a potential sanction under Rule 37(b) includes ordering that certain facts be taken as established against the non-complying party.

The purpose of a protective order is to limit or prohibit the production of information that is overly burdensome, duplicative, or infringing on privacy rights; a court might issue a protective order to limit the scope of a deposition to prevent harassment.

Summary judgment is granted if there is no genuine dispute as to any material fact and the moving party is entitled to judgment as a matter of law; the moving party must demonstrate the absence of a genuine dispute of material fact, and the non-moving party must then come forward with specific evidence showing a triable issue exists.