Actually making something simple and still look good is very hard to do.

To me art is the creative expression of a person by whatever means he or she uses.
Can be a photo, painting with coffee, a sketch, a video and anything else.

So as long as there is some creative expression in mind, I will call it art.
Even if it is done for commercial reasons.

and of course that art

I could tell you that art plays a large part in making our lives infinitely rich. Imagine, just for a minute, a world without art! (You may think "So what?" but please consider the impact that lack of graphics would have on your favorite video game.) Art stimulates different parts of our brains to make us laugh or incite us to riot, with a whole gamut of emotions in between. Art gives us a way to be creative and express ourselves. For some people, art is the entire reason they get out of bed in the morning. You could say "Art is something that makes us more thoughtful and well-rounded humans."

On the other hand, art is such a large part of our everyday lives that we may hardly even stop to think about it. Look at the desk or table where you are, right this minute. Someone designed that. It is art. Your shoes are art. Your coffee cup is art. All functional design, well done, is art. So, you could say "Art is something that is both functional and (hopefully) aesthetically pleasing to our eyes."

You might say "Art is in a constant state of change, so nobody can really pin down what it is." The constant change part is true, but the not pinning it down part is going to get you a bad grade. It may even raise a comment or two about your being some sort of wisenheimer. Don't go this route.

You might even say "Art is subjective, and means something different to every single person on earth." This, too, is the truth. I would caution against this approach, however, as it would require a stack of paper from here to the moon to cite all of your 6.8 billion references.

"Art is form and content" means: All art consists of these two things.

Form means:

The elements of art,
the principles of design and
the actual, physical materials that the artist has used.

Form, in this context, is concrete and fairly easily described--no matter which piece of art is under scrutiny.

Content, now, gets a little more tricky. Content is idea-based and means:

What the artist meant to portray,
what the artist actually did portray and
how we react, as individuals, to both the intended and actual messages.

Additionally, content includes ways in which a work was influenced--by religion, or politics, or society in general, or even the artist's use of hallucinogenic substances--at the time it was created. All of these factors, together, make up the content side of art.