A STRING is a sequential collection of Unicode characters that is used to represent text. A String object is a sequential collection of System.Char objects that represent a string. The value of theString object is the content of the sequential collection, and that value is immutable (that is, it is read-only). For more information about the immutability of strings, see the Immutability and the StringBuilder class section later in this topic. The maximum size of a String object in memory is 2 GB, or about 1 billion characters.
Please note that you cannot CAST strings to PSZ like you can in Visual Objects. The PSZ type consists of 8 bits per character where the STRING type has 16 bits per character.