Network News Transfer Protocol (NNTP) is used to transfer newsgroup postings between servers and from servers to client newsreaders. Newsgroups are one of the earliest forms of computer network communication and predate the public Internet.The best known set of newsgroups are those on Usenet. Newsgroups are a form of electronic bulletin boards where , however these bulletin boards are transferred from server to server. People wishing to browse these bulletin boards must subscribe to a group and then download the 'headers' which are a listing of the subject lines for each of the postings. Boards are sorted by topics and within the topics are threads. Threads begin with a post and are followed by a number of replies.