How is graphic design used?

Answer:

Graphic Design has a different definition depending on who you ask.
I was taught in what is called the "master ways" but in modern times, so my Personal definition I hope helps.

Graphic Design is a strategic art,
meaning that it is art that is planned to serve a particular purpose. Opposite of it's cousin, Fine Art, which typically is mainly based on/from emotions, Graphic design is usually analytical/structured.

In a modern sense, Graphic Design is Visual Problem Solving.
Therefore is used everyday in every way.
From billboards, to magazine covers, to iPod packaging, to shopping bag, even the book that you read all started out as a problem.
"How do I get people to shop at my store?" ... "I need a billboard."
What kind of store is it? What are you selling? Where are you located? Are you upscale or middle ground? These are the type of questions that I Graphic Designer would ask so that they can turn your advertising problem into a successful billboard.

Example: A chef is ready to open his own restaurant. He would contact graphic designers to bring the look and feel of his image together. The (print freelance) graphic designer would possibly come in, sit and learn about the chef, his vision, the restaurant, the cuisine, the location, ect and Solve the chef problem on not having a look and feel to his new restaurant.
Once the (print) designer has gathered all the information, he/she would present (typically) 3 possible solutions to the chef, including (but not limited or exceeding) logo, color scheme, business cards, letterhead, envelopes, menus, take out packaging, even custom packaging for the chef's "house wine"...ect.

Graphic Design is very diverse. So diverse that it can lend it's self to all kinds of genres.
Typically there are two types of designers: Print & Web
Print: Editorial, Layout, Logo, Creative Photography, Packaging, Illustration, 3D Modelings
Web: Internet/Websites, Film, Animation, Coding

But graphic design can lend itself to ergonmic, architectural, fashion, interior, furniture, product, even the medical industry.

Graphic design is design.
That makes it available to be used almost anywhere and on anything.

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