The term blog is a shortened form of the word weblog — a compound word made of web, which refers to the World Wide Web, and log, which refers to a diary or daily journal. Blogs are maintained on websites, either by themselves or in combination with other types of pages, and they may be private or commercial, kept up regularly or have sporadic entries, and be broad in scope or focus on a particular topic or subject. A blog review is one of three things. It may be an analysis and rating of a blog or group of blogs of a particular type. It may also be a type of blog that offers product and service reviews, or it may be a blog that offers reviews of performances, exhibitions, works of artistry or literature, or restaurants, paralleling the function of a newspaper critic.
The first type of blog review — the type that rates blogs — is designed to help users find the best blogs of the type they are seeking and/or avoid blogs that are poorly written, not kept up, or overrated. It is possible to find blog recommendations for outstanding blogs in general — blogs that the reviewer feels most of his or her readers will enjoy. However, some bloggers will post a specialized blog review that focuses on, for example, the best photoblogs, green blogs, productivity blogs, wedding blogs, television blogs, blogs for moviemakers, blogs for education leaders, food blogs, coaching blogs, tech blogs, travel blogs, author blogs, elearning blogs, business blogs, spiritual blogs, parenting blogs, fashion blogs, SEO (Search Engine Optimization) blogs, etc.
The second type of blog review may be the blog of an affiliate marketer, who reviews products or services hoping that people will purchase them through a link from his or her site after reading the review. Alternatively, the blog review may be paid for by a merchant. In this case, it is important for the blogger to disclose the fact of being paid to readers, for ethical reasons — and possibly legal reasons, depending on where the blogger lives. Other ethical issues include making sure that search engines are not affected by paid links by using the nofollow tag, and to give an honest opinion, even in the face of possibly losing an income stream from a merchant that only wants positive reviews.
The third type of blog review — the blog review carried out by a critic — may simply be the project of an individual who loves reading books and talking about them, for example. Alternatively, it could be part of a primarily commercial venture, such as a movie review blog hosted by an entertainment company, or the output of a person who’s found a way to monetize a hobby. It can also form part of an online social network.