Views can be stored in the database, which is typical of smaller sites and hobby sites. However, Views may also be stored directly in the code as "default" views, (which simply means they're available by default). Modules often come with views that are specific to the module data, but it's also possible -- and <b>highly</b> recommended -- that sites which have separate "development" and "production" sites export their views into default views in a site-specific module. This makes it very easy to transfer vi