What's a Pthread?

Question

I'm getting confused on the idea of "pthread" and "thread". I know pthread is short form for POSIX thread, which is a type of standardized thread used in UNIX. But people often use "thread" to refer a thread. Are pthread and thread equivalent? Or pthread is only the name for threads used in UNIX? Thanks in advance.

Answer 1

Threads are a generic concept. Wikipedia defines it as:

In computer science, a thread of execution is the smallest sequence of programmed instructions that can be managed independently by an operating system scheduler. A thread is a light-weight process.

Pthreads or POSIX threads are one implementation of that concept used with C program on Unix. Most modern languages have their own implementation of threads. From that web page:

Pthreads are defined as a set of C language programming types and procedure calls, implemented with a pthread.h header/include file and a thread library - though this library may be part of another library, such as libc, in some implementations.

Answer 2

To add to Gray,

Pthread is POSIX complaint which means you can use it across most of the UNIX operating systems.

No need to rewrite them for each of Unix (Linxux,FreeBSD, etc) and the behavior would be same across all of them .