Original
Type compatibility and identity
To understand which operations can be performed on which expressions, we need to distinguish several kinds of compatibility among types and values. These include type identity, type compatibility, and assignment-compatibility.
See also
Data types and variables: Overview
译文
类型兼容和等同
要了解哪一个操作可以作用于哪一个表达式，需要区别类型和值之间的几种兼容性。包括类型等同、类型兼容和赋值兼容。