Note: In SharePoint documentation and development, some terms are very confusing after several generations of the product. In the following list, the first term is what a cmdlet or other object may be named, while the second term is the actual current SharePoint term to which it refers:
"Web" = "Site"
"Site" = "Site Collection"
"Web Application" = "Web Application" (usually; this one seems fairly consistent.)
So, for instance, you might think that the Move-SPSite cmdlet could be used to move a SharePoint site, but you would be wrong. Move-SPSite is used to move a site collection from one content database to another. Confusing? Yes. So much so that the TechNet authors who created the pages listed above confused "SharePoint site" with "Site Collections" and "Web Applications."