Appreciate if anyone could:
1. Explain the difference between the two.
2. Explain how to choose one over the other when designing for a Sharepoint solution.
A blog and a team site are created from different site templates that define the lists, libraries, pages, features and web parts that are pre configured on the sites.
The team site is probably the most common site template used for collaboration. It provides a document library and lists for managing announcements, calendar items, tasks and discussions.
A blog site, on the other hand, is desinged for publishing periodical posts of information. It comes configured with lists to manage posts, post comments and post categories.