A peer-reviewed journal (also known as refereed or scholarly journal) is one in which each feature article has been critically examined by other scholars in the author's field before it is published. Collections of papers from conferences may be considered peer-reviewed if the original presentations were "invited" or examined by experts before being accepted.
Peer-reviewed articles are of the highest quality. However, news items, editorials as well as book and article reviews included in referred journals may not be peer-reviewed.
Peer-reveiwed journals can be identified by looking at its first and last few pages. Check to see if there is a page listing the Editorial Board, and see what credentials they have. If there is a page containing "instructions for authors", it may actually say the journal is peer reviewed. Another way to determine whether or not a journal is peer-reviewed is to consult Ulrich's International Periodicals Directory.