A more thorough explanation:

Shepard's Citations is a tool used in the legal field to track and reference judicial decisions, statutes, and other legal resources. It helps researchers to see how these resources have been used over time and for different purposes.

For example, if a lawyer is working on a case and needs to know how a particular court decision has been cited in other cases, they can use Shepard's Citations to find that information. This can help them to better understand the legal precedent and how it has been applied in different situations.

Shepard's Citations covers both federal and state courts, and provides references to when and how cases and law review articles were cited by other sources. This makes it a valuable tool for legal research and analysis.