A web page is a document that is displayed in your web browser. The only difference between a web page and a regular text document is that a web page has special markup that tells the web browser how to display it. SharePoint takes the details of the special markup and throws it behind the scenes. What you are left with is a few different types of pages you can add to your SharePoint sites:
Wiki page: Also known as a content page. You can add content to wiki pages by typing and formatting text. In addition, you can insert images and Web Parts. Adding content to a wiki page is much like working with Microsoft Word in that all the capabilities for formatting content are contained at the top of the page in the Ribbon. And as the name implies, a wiki page handles all of the wiki commands, such as the [ and ] characters.
Web Part page: A Web Part page is specifically designed for Web Parts. A Web Part page includes Web Part zones where you can add Web Parts. Using a Web Part page, you can drag Web Parts between zones and connect them to each other. You can choose from multiple Web Part zone layouts when creating a Web Part page.
Publishing page: The publishing page is used when you need to create a separation between the publishing of content and the layout of the content on the page. A publishing page allows you to create a standard page layout and then let multiple users enter content using the page layout. This allows users who are familiar with their content but not with SharePoint layouts to publish to the site while still maintaining a consistent look and feel.