Java 并发是与硬件息息相关的。Java 线程由操作系统管理，而操作系统又是运行在 CPU 之上的。

并发知识点

• Java 并发领域介绍
• volatile 关键字的应用场景与原理剖析
• synchronized 关键字的底层原理深入剖析
• Lock 原理深入剖析
• 何为原子操作以及原子操作的原理深入剖析
• 锁与锁原理深入剖析
• 锁框架详解
• 读写锁与重入锁分析
• 内存屏障详解
• Completion Service 详解
• 重排序详解
• Fork-Join API 详解
• 一致性语义深入解读
• 资源死锁详解
• synchronized 与 ReetranLock 详细对比
• happen-benfore 语义的含义讲解
• Java 内存模型深入详解
• Exector 框架深入解读
• ThreadLocal 原理与底层源码深入解读
• Java concurrent 包重要且核心组件深入详解
• CountDownLatch 详解
• CycilcBarrier 解读
• 线程间同学方式详解
• CPU Cache 模型详解
• JMM 的有序性、可见性与原子性详解
• Java 线程池深入剖析
• Future 模式深入详解
• CAS 深入剖析
• JVM 对 CAS 的支持
• 其他并发分析工具详解

jdk 文档的描述

Thread

A thread is a thread of execution in a program. The Java Virtual Machine allows an application to have multiple threads of execution running concurrently.

Every thread has a priority. Threads with higher priority are executed in preference to threads with lower priority. Each thread may or may not also be marked as a daemon. When code running in some thread creates a new Thread object, the new thread has its priority initially set equal to the priority of the creating thread, and is a daemon thread if and only if the creating thread is a daemon.