1. With respect to computer programming, a thread is a portion of code that may be executed independently of the main program. For example, a program may have an open thread waiting for a specific event to occur or running a separate job, allowing the main program to perform other tasks. A program is capable of having multiple threads open at once and will either terminate or suspend them after a task is completed, or the program is closed.
2. When referring to a computer forum, a thread consists of an original message or post and each of its corresponding responses. For example, in a newsgroup or message board, a user may post a question relating to computers; each of the replies relating to the original message are a single thread. Below is an illustration to help give you a better idea of how a thread looks.
<Original Message> user - email@example.com
Hello, I was wondering if anyone knows how to turn on a computer.
>>Joe - firstname.lastname@example.org
>>User have you tried pressing the power button?
>>>>User - email@example.com
>>>>Joe what is the power button?
>>>>>>Joe - firstname.lastname@example.org
>>>>>>The power button is usually a small round button located on the front of your computer's case.
As can be seen by the above example thread, a user can view the complete message and make any additional feedback or comments as well. A thread can refer to any ongoing communication, including e-mail.