As you can see SharePoint offers different elements to store data inside SharePoint. Each element can be seen like a container with sub elements or parent elements.
The following example shows a fictitious company:

The picture shows:
- A web server hosting two web sites: One web site for the intranet and one for the extranet.
- The intranet contains two site collections: A site collection for “sales” and “human resources” (HR) and a second site collection for the “business management” (ec).
- The first site collection contains sites for the “sales department” including a sub site called “products”. It also contains a site for “HR” with the sub sites “personal” and “benefits”.
- The sub site “products” contains lists and libraries to describe the products. For example there are presentations and white paper as well as product descriptions.
Summary
Information Workers these days have problems to make decisions based on too much information or because of insufficient information. Information is usually stored at different places, can’t be found or accessed.
The goal is to work more easily and more efficient and to securely store, manage and retrieve any information from anywhere.
Storing Information at one place is required. Microsoft offers SharePoint as part of a solution where you can store information using items, documents, lists, sites and Site Collections. You can group them into logical units to represent teams, departments, partners or projects.