Webskins are another name for a view, and basically represent the code or template that builds content to be shown to your users. This content might be an HTML fragment, a form, XML, anything at all really – it depends on your target audience and where in the site the view will be rendered.

Miscellaneous Webskins

InsertHTML Templates

InsertHTML templates are used to provide snippets of HTML to insert into your rich text editor. These templates are processed at editing time in the same manner as any other webskin.