T-TRAK is a modular model railroad system based on standards for module size, track placement, track interface, and electrical connections. The standards allow for a wide range of flexibility in design yet still maintain interoperability with all modules built per the standards. The popularity of T-TRAK is worldwide allowing for modules from all over the world to connect together.
T-TRAK modules are dioramas with sectional track, specifically Kato Unitrack, that snap together to create layouts from a simple circle to large complex layouts. The modules are designed to fit on tables. Layouts are easy to assemble and disassemble. The convenient size of the modules make them easy to store on a shelf or in totes when not in use, or to transport.
Reading the history of T-TRAK helps to understand the reasoning behind the standards. Trying to keep this up-to-date is a challenge as this is a rapidly growing area of N Scale model railroading.