Perspective is the technique used to represent a three-dimensional world (what we see) on a two-dimensional surface (a piece of paper or canvas) in a way that looks realistic and accurate, as we see it in nature. Perspective is used to create an illusion of space and depth on a flat surface.
Young children, while being creative, have little understanding of perspective. Ask a 5 year-old to draw a box and she will probably draw a square with height and width. However, someone with perspective would add depth to the picture and create a cube.
Perspective is also the relationship of objects to each other and to the picture as a whole. If you want to paint a landscape with a field in the foreground, trees in the mid-ground and hills in the background, you will have to create the spatial relationships of the objects to each other - their distance from each other in terms of size and the effects of distance in their appearance. For example - the colors of hills in a background seem to fade. They get lighter as they get farther away. Incorporate this into your painting and you give the illusion of depth and distance.
There are aspects of gaining perspective in art that can be translated into gaining perspective in life. I like finding depth and meaning in what I do, where I am, and who I interact with. I'm big on purpose. I find that when I lose perspective, I tend to lose my sense of purpose too. Here's an example: I'm a GED instructor at a correctional facility. Last week, I had one student blow off class. All the hard work we had done didn't matter to him, nor did the fact that the test was only three weeks away. He was done because he didn't feel like doing the work. I got mad and then I got discouraged. Was I beating my head against a wall? Were my attempts at making a difference futile? Should I quit? These questions got me in a funk, and it wasn't until the next day that things started turning around. I was driving to work when this thought meandered into my consciousness. I had focused on one student who blew me off and I had lost sight of the four other students who were sitting in class, working hard, and making me proud! In that little moment I gained perspective. Nothing earth shattering, but important to me nonetheless.
Another definition of perspective is this: the ability to see all the relevant data in a meaningful relationship.
The ability to see all the relevant data in a meaningful relationship - seeing the whole picture.
Perspective is one of those words that's a little dull like the words "objectivity" and "sensible". It doesn't dazzle like "ephiphany" or "paradigm shift." For all that, it's hard won and wears well for the long ride.