While there are virtually no limitations to the possible variety of garden styles, several traditional and natural styles have given inspiration to landscapers for centuries.
Before travel between countries grew to become common, these styles were insular, developing slowly over 1000's of years.
Countries across the world evolved quite different kinds of garden design, with the styles driven by factors like climate, common land form, local materials, social factors and in some cases religion.
As people began to travel, garden styles inevitably started to blend together.
This has led to many interesting designs, such as the development of the Japanese garden style from its earlier roots in China.
Pairing two or more styles is usually very effective, and can be achieved by dividing your garden into smaller 'rooms' with trellis or decorative hedges.
Even in compact areas, stylistic contrasts may well offer an interesting change of key: the strong, fresh lines of a modern, formal pond may be effectively counterbalanced by a background border overflowing with old-fashioned rambling roses and dazzling annuals.
Nevertheless, you ought to plan the connecting of areas with great care, to avoid creating a discordant effect.
The most important principle to understand is the reason why these various garden styles were developed, and after that to draw inspiration from them.
You'll then be able to appreciate the objective of a specific style of garden, and why it works so well, enabling you to create your own personal style which will suit your needs.
Whatever styles of garden you choose to adopt, make sure you take pleasure in the process itself rather than just striving for an end result.
Studying and developing your garden style can be extremely gratifying in itself.