A microblog is a form of a blog where people send short messages of text or media (pictures, video, or sounds). These messages can be sent to a website and shown to either a small group or to the public. A "microblogger" (someone who uses a microblog) could send their messages from different sources including cell phone text messages, email, instant messages or through a website.
A microblog is usually different from a normal blog. It has much smaller pieces. A microblog entry can be just one sentence, or a link to an image or short video. A person writing a microblog can use many ideas from "what am I doing now," to Race cars or politics or information about their business or personal life.