Technical drawing

Technical drawing, also known as drafting or draughting, is the act and discipline of making detailed drawings. These drawings visually communicate how something works or how it is to be made.
Communicating ideas.
Technical drawing is essential for communicating ideas in industry and engineering. 
To make drawings easier to understand, people use familiar symbols. They use standard units of measurement, notation systems, visual styles, and page layouts. These drawing conventions are internationally accepted standards. Technical drawings are a universal way of communicating complex mechanical concepts. Technical drawing are very different from the expressive drawing of the visual arts. Artistic drawings may have many meanings. Technical drawings are understood to have one intended meaning.
Technical drawings are used to make electronic parts as well as mechanical parts. They are used in commercial and residential construction. Roads, bridges, and wastewater systems are just some of the things that need technical drawings. Almost anything that is manufactured requires technical drawings. 
Technicians.
A drafter, draftsperson, or draughtsman is a person trained to make technical drawings. A professional drafter who makes technical drawings is sometimes called a drafting technician. Professional draftspersons bridge the gap between engineers and manufacturers. They contribute experience and technical expertise to the design process.