Local & Global resources
When localizing your ASP.NET websites, you can store your resources as either a local or a global resource. A local resource is specific to a certain page, which is the only one who can access it, while global resources can be accessed from anywhere.
Local resources are kept in the special App_LocalResources folder, while global resources are kept in the App_GlobalResources folder. Local and global resource files will look exactly the same, so the only apparent difference, is the folder they're placed in. However, they are used differently. For instance, with local resources, you need a resource file for each of your pages, and an extra one of each of the desired languages. So if you have a website with 10 pages, each localized into two other languages, besides the default language, it will amount to 30 resource files. With global resources, you would only need (but not be limited to) one file per language, no matter how many pages you have. On the other hand, each of these files could get pretty hard to manage, if your site has lots of localized content.
You will likely always need some global resources, but if you prefer, you may skip the local resources and only use global ones. It's really up to you.