Difference between initWithNibName and initWithCoder

From Apple's Documentation:

InitWithCoder encodes an object for archiving. A coder instructs the object to do so by invoking encodeWithCoder: or initWithCoder:. encodeWithCoder: instructs the object to encode its instance variables to the coder provided...

InitWithNibName Returns an NSNib object initialized to the nib file in the specified bundle. After the nib file has been loaded, the NSNib object uses the bundle’s resource map to locate additional resources referenced by the nib. If you specified nil for the bundle parameter, the NSNib object looks for those resources in the bundle associated with the class of the nib file’s owner instead. If the nib file does not have an owner, the NSNib object looks for additional resources in the application’s main bundle.

The former is used for encoding individual objects in your code, the latter is used to retrieve a NSNib file containing resource objects.