Blogs often provide commentary or news on a particular subject, such as food, politics, or local news; some function as more personal online diaries. A typical blog combines text, images, and links to other blogs, web pages, and other media related to its topic. The ability for readers to leave comments in an interactive format is an important part of most early blogs.

The author of a blog is often referred to as a blogger. Many blogs syndicate their content to subscribers using RSS, a popular content distribution tool.

A blog comprising videos is called a vlog, one comprising links is called a linklog, a site containing a portfolio of sketches is called a sketchblog or one comprising photos is called a photoblog. Blogs with shorter posts and mixed media types are called tumblelogs.

Blogs can also be defined by which type of device is used to compose it. A blog written by a mobile device like a mobile phone or PDA is called a moblog.

Some blogs focus on a particular subject, such as political blogs, travel blogs, fashion blogs, project blogs or legal blogs (often referred to as a blawgs).

A blog can be private, as in most cases, or it can be for business purposes. Blogs, either used internally to enhance the communication and culture in a corporation or externally for marketing, branding or PR purposes are called corporate blogs.

Several blog search engines are used to search blog contents (also known as the blogosphere), such as blogdigger, Feedster, and Technorati. Technorati provides current information on both popular searches and tags used to categorize blog postings.

Everyone's jumping on the blogging.Now anyone who fancies himself a writer, and even some people who don't, has a blog on the Internet. Thanks to easy-to-use programs and websites, the most technically challenged person can get a blog online. This isn't a bad thing, as there's something out there for everyone.