The Bytes datatype is used to store binary data (i.e., a sequence of octets) and is manipulated by the Bytes class functions.

A Bytes acts like a String, in that it is immutable and logically copied when it is assigned or passed as a parameter. Unlike a String, however, the subscripting and concatenation operations do not apply to the Bytes datatype. Instead, the corresponding Bytes built-in functions must be used.