What is "compilation-directives"

1. Instruction or set of instructions for the execution of a plan, an action, an enterprise etc.
2. Procedural rule.
3. Directive is a construction of some programming languages that specifies how the compiler or assembler should process the source code. In some contexts, directives are known as pragmas.

In Assembly, directives generally specify information such as Target platform, separate sections of code, and so on. Already in C and C++, the language supports a macros preprocessor, and the code which must be passed by the preprocessor is indicated by directives of preprocessing, such as #define and #include. In Turbo Pascal, the directives are called significant comments, because in grammar of the language they follow the same syntax of the comments. Thus, a significant comment is a comment whose first character is a $, and whose second character is a letter. For example, the equivalent to the #include "arquivo" of C is the significant comment {$I "file"}. In Perl, the keyword use can introduce a pragma, such as use strict; or use utf8;