What is the term for a system of tracks used for making up trains and storing cars?

The term for a system of tracks used for making up trains and storing cars is known as a "yard." In railroading, a yard serves as a crucial area for the organization and management of rolling stock. It is designed to facilitate the assembly and disassembly of trains. Trains can be broken down and cars sorted into various classifications based on their next destinations or cargo types within the yard.

Yards are typically equipped with multiple tracks and may include various facilities for maintenance and repairs, enhancing operational efficiency. The function of a yard is distinct from that of other track types, such as a siding, which is primarily a short section of track that allows trains to pass each other, or a main track, which is the primary route for trains traveling long distances. A depot, on the other hand, is a structure where passengers and freight are handled, inconsistent with the purpose of a yard in rail operations. Thus, "yard" is the most accurate term for the described system of tracks.