Will you use a trellis to grow apples? What type of trellis is it? V trellis?

I am collecting information about apple planting and have many recommended images for v trellis. What type of trellis would you use?  When should I use it? Are there any other recommendations besides these? Like bird nets, fruit bags, etc?

Intriguing, we have apple trees and don't trellis them. Does the trellis assist in protecting the fruit for birds?

I suppose if you use really dwarfing root stocks, the trees may need some support, although I thought it was just the trunk that needed support. My parents grew cordon fruit as a garden divider when I was a child, but that was a very simple system. It was somewhat like this - with the trees put on the diagonal:

cordon fruit tree garden divider

(source)
In this way they had several varieties of apples and pears in a very small footprint. It was practical in a small garden to do this. There are obvious downsides of very dwarfing rootstocks as I understand it: they tend to be rather shorter lived, and susceptable to diseases. Apart from a lot of summer pruning, there was very little other maintenance required.
I think in a larger space like pictured above I'd rather have more variety, more vigorous trees, and interplant with other trees and flowers to provide habitat for the natural pest controllers.

Sena Kassim wrote:Intriguing, we have apple trees and don't trellis them. Does the trellis assist in protecting the fruit for birds?

I find that using a trellis system can have a certain effect on protecting fruits from bird infestation, and it might be better to add fruit protection bags or bird nets to this foundation.