A vlog is a video blog post. The term can also refer to a blog made up entirely of video blog posts.
Vlog posts are created by creating a video of yourself or an event, uploading it to the Internet and publishing it within a post on your blog.
In the early days of blogging, vlogs were called podcasts, a term that was used to refer to both audio and video blog posts. Today the two have adopted their own distinct nomenclature.