Transaction Level Modeling provides the communication foundation for class-based UVM environments. Components exchange transactions through typed methods rather than direct signal-level coupling. This makes drivers, sequencers, monitors, scoreboards, coverage collectors, register models, agents, environments, and testbenches easier to connect, replace, and reuse. Communication behavior is described through data flow, control flow, timing behavior, and connector roles, giving each connection a clear technical meaning. Data flow defines the movement of transaction items from producer to consumer. Control flow defines the initiator and target relationship. These two directions determine whether a connection is pull-based through get methods or push-based through put methods. Blocking methods allow a transfer to wait until completion, while nonblocking methods return immediately with success or failure. Method families such as put, try_put, can_put, get, try_get, can_get, and peek provide precise choices for transfer control and readiness checking. UVM TLM connectors define the structure of the communication interface. A port starts the call, an imp provides the implementation, and a...