Architectural style constitutes a mode of classifying architecture largely by morphological characteristics in terms of form, techniques, materials, etc.. However it is not a holistic way of understanding architectural works because of its emphasis on style. It overlaps with and emerges from the study of the evolution and history of architecture but it is slightly different in its emphasis. While in architectural history, the study of say an area like Gothic architecture would include all the aspects of the cultural context that went into the making of architectural works, architectural style is a way of classifying architecture that gives emphasis to the characteristic features of Gothic architecture, leading to a terminology such as Gothic style. This could then apply equally to buildings even produced during periods outside the historic period of Gothic architecture. Thus one could build a Gothic style church even today irrespective of the historic period from which the style emerged.
In the 19th century, architecture of the past was understood from a formal perspective, emphasizing the morphological characteristics of form, technique and materials.
In these respects, architectural history is a subdiscipline of art history that focuses on the historical evolution of principles and styles in the design of buildings and cities.
The establishment of architectural history as a discipline in the West is reflected in the greater historical clarity of western architectural development, whilst the understanding of non-western architecture often proceeds with less historical context.
It is that architecture is man's most self-revealing record of his struggle upward from barbarism to the complex civilization of today.
Architecture, though the aesthetically sensitive may rail at it, is thus a prolific source of historical data, a most comprehensive and interesting text-book of which I shall make frequent use, and shall do my best to interpret simply and, I hope, interestingly.
Accepting, then, the dictum that architecture is a record of man's development, we seek first the basic forces, or motives, in the human advance, so that we may find the primary sources of architectural inspiration.