Site Definition and Web Template are used for building a SharePoint site. If you are new to SharePoint, you may wonder which one to use?. Well, it depends on your site requirements and extensibility. Both are used to build a site UI interface to the end user.  The major difference is a Web template is always based on a existing Site Definition either directly or indirectly. I have outlined some comparisons in the below table Read more

A SharePoint site definition is the core definition of what a site in SharePoint. A site definition can include more than one site definition configurations i.e. family of configurations.  A configuration specifies the sets of lists, Features, Modules etc. that are included when a new site is created. Read more