Formal systems, studied by logicians, mathematicians, philosophers and others, are (usually) characterised by a specified and restricted set of symbols, rules for making statements from those symbols, plus rules for generating new statements. So from these basic rules and instructions, statements can be generated that are regarded as products of the system; they are called theorems.
In our professional lives, we are surrounded by and endlessly use and manipulate information and systems that are based on formal logic. The worlds we occupy are structured by theories, models and systems that are more or less logically coherent. If our aim is to make the world a better place, then starting with an understanding of logic beyond the simple analysis of arguments is a necessity.