Define the term assembler directives.
An assembler directive is a statement to provide direction to the assembler to perform the function of assembly process. The assembler directives control organization of the program and give essential information to the assembler to understand assembly language programs to produce machine codes. They specify how an operand or section of a program is to be processed through the assembler. An assembler assists directives to explain data, to organize segments to control procedures and to describe macros.