Literals are the notational method whereby numeric values or strings of character data are represented in the source stream. Literals are also commonly referred to as constants (especially in the context of high level languages) because they typically represent objects whose values do not change throughout the life of the assembly or compilation. However, literals should not be confused with run-time "constants" ("read-only" data items allocated by the programmer); they are assembly-time tokens used by the assembler to represent numeric values or character strings.