Huh? Dont know what a podcast is? Check out Wikipedia

From WikiPedia:

"Podcasting is a means of distributing audio and video programs via the Internet that lets users subscribe to a number of files, also known as "feeds", and then hear or view the material at the time that they choose. A feed is usually in the MP3 audio format.

Podcasting became popular in late 2004 with the spread of free software that enabled automatic downloading of audio MP3 files onto computers and mobile MP3 players.

"Podcasting" is distinct from other types of online media delivery because of its subscription model, rather than one-time delivery. A series of files are delivered because subscribers want to get the information regularly."

A shared on-line journal where people can post diary entries about their personal experiences.
Postings on a blog are usually in chronological order and have often have comments from other users

Business's use blogs to communcate with their customers. You use blog to build a stronger relationship with your customers and bring a greater sence of brand loyalty. Customers love to see the insight that goes on within a business, and a blog is the best way to offer your customers better access to your business.