There are no clear guidelines that can help you differentiate between a blog and a website. When people talk of a blog it is likely that they are referring to a website that publishes blog posts listed from the latest on the homepage (in terms of dates).
Most blogs are also run by an individual or a small editorial team whereas websites are considered to be run by a large team of professionals.
- An example of a blog is: Problogger.com
- An example of a website: cnn.com