1. A series of discussions posted on a listserver, Usenet newsgroup, or conference that deals with the same subject. From Faculty-of-Education

2. A small piece of programming that acts as an independent subset of a larger program, also called a "process". A multithreaded program can run much faster than a monolithic, or single-threaded, program because several, or even many, different tasks can be performed concurrently, rather than serially (sequentially). Also, threads within a single application can share resources and pass data back and forth between themselves. From I-gloss