A Web application is an IIS Web site that is created and used by SharePoint Products and Technologies. Each Web application is represented by a different Web site in IIS. Whenever a new Web application is created, a new content database will be created. By default (unless specified during creation) site collections created in the Web application will be placed in the Web application database.

SITE

Site = Web = SPweb aka sub web

A site is a collection of lists, libraries, and pages. Whenever you create a new site, a template for the site must be chosen. The templates available out of the box will differ depending on the SharePoint version that is installed. Sites are sometimes referred to as 'webs' also.

• A site is a web is an SPWeb to developers, and a Sub web to old timers or sub-site to those just trying to use something to distinguish it from a site collection.
• STSADM - Site is a Web; 'Stsadm -o enumwebs' would enumerate a list of sites for a site collection.
• In the Site Settings UI the site is most often referred to as a site, for example the ability to create sites and workspaces would be referring to sites within the site collection.
• In the Central Admin UI it would be referred to as a web.
• SPweb = to a developer they would iterate through a list of SPwebs for an SPsite.

Site Collection

Site Collection = SPSite = Portal = Sometimes referred to as a 'Top Level Site'.

A site collection is a set of Web sites that have the same owner and share administration settings. Each site collection contains a top-level Web site and can contain one or more sub sites. In short, a site collection is a 'container' that holds sites or webs.
Here are a few of the key characteristics of Site Collections

• STSADM - Site 'Stsadm -o enumsites' would give you a list of site collections in a web application
• Central Admin Site - Limiting the number of sites in a database is limiting the number of site collections per database
• Developers - 'Site = SPSite' would be the equivalent. The SPsite would be the container and would have SPwebs on the inside.

• Smallest unit for controlling storage database
• Sites are backed up at the site collection level
• By default, security is managed at the site collection level
• Quotas can be configured for site collections
• Sites are confined to share content within their own site collection
• Level of ownership is defined at the site collection level.

Master Pages

Master pages in SharePoint work the same as they do in traditional ASP.NET applications. They allow designers to control almost all aspects of the overall layout of a SharePoint site. Master pages can be thought of as the glue that holds all of the SharePoint functionality together. In fact every SharePoint site will have a master page, whether it is custom or one of the out-of-the-box master pages. When a designer creates a custom master page, they are typically trying to make a SharePoint site look less like it does out of the box and more like a company’s specific brand.

Master pages are stored in the master page gallery of a SharePoint site. They can be added to the master page gallery either directly from either SharePoint Designer or the SharePoint Web interface, or they can be deployed via a Feature.

Master pages are applied to an Office SharePoint Server site via the Master Page settings menu located from the Site Settings of the SharePoint Web interface. One really nice thing about this menu is that it allows the administrator to apply a master page not only to the current site, but to all sub sites below it. Along with this manual method, master pages can also be applied to SharePoint sites via custom Features. Master pages can also be applied to Windows SharePoint Services sites. Like Office SharePoint Server sites, the master page is stored in the master page gallery. Unlike Office SharePoint Server, changing the master page can only be done through a custom solution.

• Customizing and Branding Web Content Management-Enabled SharePoint Sites  -  http://msdn.microsoft.com/library/aa830818.aspx

Themes

SharePoint themes are different from ASP.NET themes; they are used specifically to change the colors, fonts, and some of the images that are used in SharePoint sites. Unlike master pages though, they cannot be used to move SharePoint elements or change the layout of the page. They are created entirely with CSS and images and cannot use any custom ASP.NET code.

SharePoint themes are typically added by manually logging into the physical server and copying the various files (images, CSS, and XML) to several folders in the 12 directory. They are applied from the Site Settings menu in the SharePoint Web interface.

For more information on creating SharePoint themes, refer to the following articles:

• How to: Create New SharePoint Themes  -  http://msdn.microsoft.com/library/aa867986.aspx

• How to: Apply a SharePoint Theme          -  http://msdn.microsoft.com/library/cc621346.aspx

Master Pages vs. Themes

While both master pages and SharePoint themes can apply branding to a SharePoint site, they differ in a few key ways. The following table highlights these differences.

Site Templates

A site template is a file that dictates the overall look and feel of a site. It includes all of the design information about a site, such as:

• The lists within a site.

• Any Web Part Pages within a site.

• Any custom pages within a site.

• The theme or Master Pages applied to a site.
• Any customizations to the Quick Launch.

• Site content (list and document library contents — optional).

Site templates do not include the following items:

• Security settings, such as a list of users or groups with permissions to the site from which the template was created.
• Personalizations to Web Part Pages.

• Web discussions from the original site.

• Alerts from the original site.
• Web part assemblies that were added to the original site.

Content Types

A content type is a reusable collection of settings you want to apply to a certain category of content. Content types enable you to manage the metadata and behaviors of a document or item type in a centralized, reusable way.

A content type is an object that defines several elements of a piece of content, including:

• Document Template that the content will be based on
• Columns that the content will have associated with it (metadata)
• Workflows that the content will use
• Information Management policies that apply to the content
• Conversion types for the content

Additionally, content type can include the following information:

• The metadata, or properties, you want to assign to this type. These are represented by columns added to the list or document library when you add the content type.
• Custom New, Edit, and Display forms to use with this content type.
• Workflows available for items of this content type. These can be defined to start automatically based on a selected event or condition, or through user selection.
• For document content types, the document template on which to base documents of this type.
• Any information necessary for custom solutions associated with this content type. You can store this information in the content type as one or more XML documents.

Page Layouts

Only available in Office SharePoint Server sites, page layouts provide yet another means for designers to style the content of a SharePoint site. While master pages provide a unified outer shell design for a SharePoint site, page layouts define the specific look and the editable data for various types of pages. They allow another level of granularity by allowing the same type of data to be shown in different ways, like an article page or a welcome page, while still utilizing the same master page. Page layouts are created in SharePoint Designer and are based on SharePoint content types and site columns. From an administrative standpoint they are added to Office SharePoint Server sites in a similar fashion to master pages. They are also stored in the Master Page Gallery and can, like master pages, can be added from SharePoint Designer, the SharePoint Web interface, or deployed via SharePoint Features.

              Page layouts help dictate the overall look and feel of a Web page. A page layout relies on a content type to determine the kind of content that can be stored on pages that use the page layout. Content for the page is stored in fields on the page. When you view or edit a page, the content is displayed in field controls. When you create a page layout, you add field controls using a Windows SharePoint Services-compatible Web authoring tool, such as Microsoft Office SharePoint Designer 2007.

             The types of fields on a page are determined by the content type for the page. Each content type contains columns that correspond to the fields on the page. When you create a content type, you add column templates to the content type for each field. Column templates determine the default field control that is associated with the columns as well as the kind of content the field can contain, such as a single line of text, a hyperlink, or a picture.

Content types for page layouts are based on the Page content type and contain the columns for the fields that can be used on pages based on the page layout. The Page content type is a system content type template created by the Publishing Resources feature. The column templates from Page will be added to all Pages libraries created by the Publishing feature.

By default, the Page content type contains a number of columns that page layouts require. The following table describes a sample of these default columns.

Page layouts are stored in the Master Page Gallery, which is a document library that is created when you install Microsoft Office SharePoint Server 2007 The Master Page Gallery is a catalog, which means that it does not appear in Office SharePoint Server 2007 lists.

Features and Solution Files (.wsp files)

Features and Solutions are an important concept for administrators to understand. They can make the management and maintenance of a farm much easier when used together. Features provide the ability to define a piece of functionality that can be turned on and off at a given scope, such as the site collection, site, or Web application. Solutions provide the ability to package and install a feature much like a Windows ‘.msi’ file, and have one installation and deployment point for all servers in the farm. The deployments can be scheduled and whenever new servers are added to the farm, the existing solutions are automatically deployed to the new server. Developing functionality as Features and deploying them as Solutions is the recommend deployment strategy for SharePoint customizations.

For more information on the benefits of using solutions and features, refer to the following:

• Solutions Overview                  -  http://msdn.microsoft.com/en-us/library/aa543214.aspx

• Solution package components  -  http://technet.microsoft.com/library/cc263289.aspx

• SharePoint Features                 -  http://msdn.microsoft.com/library/bb861828.aspx
• SharePoint Solutions                -  http://msdn.microsoft.com/library/bb862721.aspx