Web Application Architecture

Web front end-Hosts web applications that users access with a browser or other types of client
Application Services - hosts service applications and Central Admin
Sql Server - Database

File Locations and Storage
-Some resources always come from the file System
--Core list definitions
--Application pages
--Core user controls
--More
-Some always come from the content database
--List items
--Documents
-Sometimes it depends on the state of the resource (User customization)

Configure Management
-Do not directly edit files that SharePoint Installers
-Use solution packages
-SharePoint will keep the servers in the form in sync.

Security, Safety and scalability.
-SharePoint Designer based customization could be dangerous
-Inline code blocks
-Unapproved controls and web parts
-Too many controls on a page

Sharepoint provide safety
-SPRequest HttpModule
-SPVirtualPathProvider
-SPPageParserFilter
-Safe Mode processing

-Adding a control is allowed but inline code block not allowed by default
-In order to allow inline code blocks, add following in in web.config in tag


entry in config to allow rendering the control.

Form and Sandbox
-Files in Sharepoint root are deployed as farm solution.
-Farm solution deployment requires admin access to the form.
-Problem for hosted and governed environmrnts
-Sandbox solutions provide a safe alternative
-Sandbox solution pages are subject to Safe mode
-Additional  restriction apply.