Trace how Java runs statements in `main`, enters method calls, returns to the caller, and moves through loops or branches in a single ordered path. You will use this model to tell what must happen before what when no other execution path is involved.

Recognize `Runnable` as Java work with no returned value and `Callable<T>` as work that can produce a value or throw an exception. You will distinguish defining a task from actually running it, including why calling `run()` or `call()` directly still stays on the current path.

Reason through two paths of execution whose steps may overlap in different valid orders. You will separate facts guaranteed by each path’s own order from outcomes that depend on scheduling and timing.

Apply the previous explanations in a guided problem.

Mark the places where a path cannot keep going until something happens, such as a result becoming available, I/O finishing, or a resource being free. You will compare real waiting for a condition with merely hoping enough time has passed.

Inspect task scenarios for shared mutable objects, counters, files, logs, console output, or external connections. You will predict why shared resources can cause mixed output, lost updates, delays, or surprising order before learning the specific protection tools later.

Apply the previous explanations in a guided problem.

Check your understanding with a short quiz.

Review this chapter with practice based on your mistakes.