A null-terminated String. You can pass a regular REALbasic String to it and it will be terminated with a null byte automatically.
Also, CString does an implicit type conversion to String when you assign a CString to a String variable.
CString can only be used with the Declare statement and cannot be used to declare REALbasic variables, properties, or methods.
See Also
Declare statement; Byte, CFStringRef, OSType, PString, Ptr, Short, UByte, UShort, WindowPtr, WString data types.