Documentary ?Evidence & the Right of Discovery. Describe the difference between ?primary and secondary evidence

 Documentary  Evidence & the Right of Discovery. Describe the difference between  primary and secondary evidence. Also discuss the discovery process as it  pertains to the trial process. 

Brief:

Miranda v. Arizona, 384 U.S. 436 (1966).

Dickerson v. U.S., 530 U.S. 428 (2000).

Brady v. Maryland, 373 U.S. 83 (1963).