Seen here is a fascinating example of an ‘espaliered’ fruit tree in North Cave, England; which according to Wikipedia:
Espalier is the horticultural practice of controlling woody plant growth for the production of fruit, by pruning and tying branches to a frame, frequently in formal patterns, flat against a structure such as a wall, fence, or trellis.
Espaliers, trained into flat two-dimensional forms, are ideal not only for decorative purposes, but also for gardens in which space is limited. In a temperate climate, they may be planted next to a wall that can reflect more sunlight and retain heat overnight or planted so that they absorb maximum sunlight by training them parallel to the equator. These two facts allow the season to be extended so that fruit has more time to mature.