There are lots places in msdn sharepoint forums and blogs where these terms are used and I am confused between them. Can anybody clarify?
Let me see if I can explain pages in SharePoint without making you even more confused.
The difference between the different kind of pages very much depend on whether your view is as developer or as end user. As you're refering to MSDN I'll start with the developer view.
SharePoint Pages from a developer point of view
From a developer point of view there are three main kind of pages in SharePoint: Application Pages, Master Pages and Site Pages
Application pages are pages stored in a folder below
Master pages are just ordinary ASP.NET master pages which can be used to control the part of the html which is common to all pages in a Site Collection, like overall layout and navigation. The contain ContentPlaceHolders which is then replaced by the content of Content controls on the individual pages.
Site Pages are a very special kind of pages. They are (at least initially) usually stored in the folder for the corresponding Feature/Site Definition. They become available through a
Site Pages are the pages you'll normally let the end users use. They come in a number of variations:
Pure site pages
(My own term) Standard ASP.NET pages where the developer controls what's on the page. Very uncommon.
Web Part pages
Pages inheriting from
The new way of creating content pages. Very similar to web part pages, but instead of having multiple web part zones it usually only have one which is hidden. It then has a Wiki field which can easily be edited and can contain markup which will make the web parts from the hidden zone appear inline in the content (as divs)
It can be combined with multiple WebPartZones to allow more control of placement of web parts.
Publishing Pages/Page layouts
From a developer point of view publishing pages isn't really pages, but listitems which is bound to a Page Layout. The Page layout on the other hand is almost what I call pure site pages, but can only be displayed by a corresponding publishing page listitem, they contain controls which allows display/editing of the columns in the listitem.
SharePoint Pages from a end user point of view
Settings pages = Application pages
Pages where they can change some settings, but have no control of what's on the page
Web Part pages
The standard type of page in a site which started as a blank site. Allows the end user to put web parts in different zone, which makes them ideal for building "mashup" application, but hard to create ordinary content in.
The standard type of pages in collaboration sites. Allows very easy editing of content and the mix-in of web parts when needed. Very good for unstructured content.
The standard type of pages in publishing sites. The structure of the content is very much controlled by the page layouts, usually very limited use of web parts. Very good for making the site look consistent.
Wiki page is like wikipedia pages. We allow user to edit the pages.
Application page is the page which we can use the same page in different site collections or websites. Suppose if we want to show custom error page with nicely designed interface in each of our site collection then we can create an application page and give the redirect url to that application page. Application page cannot be edited by user. We should edit with visual studio. Programming knowledge require to edit.
Webpart page is nothing but the where we can add webparts to a page. We cannot add webparts except this webpart page. It will internally take care of how the webpart should render in a page etc.
Publishing page Publishing pages are available only in publishing sites. In publishing sites, authors and approvers use the publishing feature to create content and then make it available for site visitors. Usually, a publishing site has an approval workflow enabled, so content is reviewed and approved prior to being published.
See this link You can find this link by googling.
The video series SharePoint pages I: An introduction on the Microsoft Office website describes the differences between wiki pages, web part pages, and application pages from the viewpoint of a business user. Note: Application pages are referred to as system pages in the video series.
To summarize the video series:
Application pages provide tools for working with the SharePoint site, but a business user cannot edit an application page. When looking at the URL, all application pages reside in the /_layouts/ folder.
A business user can edit wiki and web part pages. Wiki pages are newer and easier to edit; web part pages are older and more difficult to edit.