Answer to Question 1
Student answers will vary, but should include reference to social networks broadening their offerings to become more portal-like. An example answer is: While Facebook can be a primary destination, the goal of Facebook is to keep users occupied and communicating with each other. One of the main goals of a portal is to provide avenues to third party content and other areas of the Internet. Although social networks are aiming to include portal-like features, to keep and grow audiences, the primary goals of a portal currently don't include social sharing.
Answer to Question 2
Social networks involve (1 ) a group of people, (2 ) shared social interaction, (3 ) include common ties among members, and (4 ) include people who share an area for some period of time.