The DLL file type is primarily associated with 'Dynamic Link Library'. A .DLL file is a support file and is used by one or more programs. As an example, if several parts of a program need to perform the same action that action may be placed into a .DLL file (library) that the various program parts can all use. This saves space and makes it easier when that particular routine needs to be updated. You should never have a need to "open" a .DLL file on its own; indeed, there really is no way to do so. Note: This file type can become infected and should be carefully scanned if someone sends you a file with this extension. If you want to look at the resources in a DLL library you can use a program like XN Resource Editor but be careful as messing with a DLL file can seriously damage Windows or programs if you do the wrong thing.
