Threads communicate primarily by sharing access to fields and the objects reference fields refer to. This form of communication is extremely efficient, but makes two kinds of errors possible: thread interference and memory consistency errors. The tool needed to prevent these errors is synchronization.

• Thread Interference describes how errors are introduced when multiple threads access shared data.
• Memory Consistency Errors describes errors that result from inconsistent views of shared memory.
• Synchronized Methods describes a simple idiom that can effectively prevent thread interference and memory consistency errors.
• Implicit Locks and Synchronization describes a more general synchronization idiom, and describes how synchronization is based on implicit locks.
• Atomic Access talks about the general idea of operations that can't be interfered with by other threads.