What's in a garden? Well plants for a start, some paths and a bit of lawn, sometimes water but all together that doesn't make a garden. The one thing a garden always has in it that the natural world doesn't necessarily, is people. The reason for this is a garden is a human invention, a view of nature, of the natural world and of how we see our place in the scheme of things. Without our help nature would soon return the spaces we occupy to a "wild" state starting with a few weeds here and there which will colonise the ground providing habitat for insects and birds bringing seed and larger varieties of plant material.
The modern garden had a long row to hoe to get to where it is today and the human view has many different purposes and variations. A classical garden with lots of topiary, hedges and symmetry is all about the control of nature, human dominance over nature, a delusion rather than ability. This is an attempt, along with classical architecture, art and feats of engineering, to try and set ourselves apart from nature. It's an ego trip, but I can be a fun one.
Another idea of gardening emerged during the beginning of the industrial revolution. This was the so-called "Landscape" garden. Perhaps this is where we get the term today. Instead of the tight geometric arrangements that had preceded them, landscape gardeners arranged nature in more natural way, introducing rolling lawn areas and more park-like effects with less symmetry, natural looking ponds and water features and more eclectic plant arrangements. These ideas originated in the large estates of Europe. They usually contained a woodland area which was more or less left to its own devices. As this style of landscape or garden design developed many designers made the wooded areas more prominent, bringing them closer to the house.
Many of our ideas of the world and our place in it were being challenged at that time. Instead of taking for granted that we were the lords of the earth, there was the beginning of an understanding that we were actually part of something larger instead.