4.4. Planning Site Collection Implementation
Once you've decided which types of portals, sites, and subsites you need to fulfill your goals, you need to determine how to implement your decision across the site collection. Every site in your site collection exists in an overall, hierarchical structure, and they are stored in the same SQL Server. Often, sites within the collection will draw upon common resources such as document and graphics libraries, links lists, permissions, template galleries, and content types.
Site collection structure is usually planned from the top down, as previously mentioned. You've already made some portal site decisions based on the audience. The following are some ways to implement those decisions.