The architectural drawing is a series of lines and marks made on a page, whether physical or digital, that represent buildings, parts of buildings, or intangible properties of buildings. The representation can take the form of annotation, in which elements of buildings are referenced through symbol, or likeness, with such drawings appearing to the viewer as sharing an appearance with the building it represents. The architectural drawing is the mechanism through which architects develop their design ideas and communicate them to the profession and its stakeholders. As a result, they range from the rough unscaled sketch performed on site, to measured projections and fully-developed instructions. 

Orthographic Projection

Most architectural drawings use the principles of an orthographic projection and are a type of parallel projection. Primary projections favor one side of an object, where the image plane receiving the projection and object face are parallel. Plans, sections, elevations, are all products of primary projection. When the object face and image plane are not parallel, and therefore depicting multiple sides the resulting image is an auxiliary projection. The isometric at 45 degrees remains the most popular form of this drawing.

An architectural detail is not clearly a specific category of drawing, unlike the others. It is a highly detailed drawing showing the juncture at which varying and diverse materials meet in a building. It is most often depicted in orthographic projection but can appear as a constructed perspective. The detail can often express the entire design concept in one drawing, because it is a manifestation of the architect’s approach to the problem of construction, organization, and coherence.

Constructed Perspective
The constructed perspective is a measured architectural drawing which represents real space through
an illusion on a two-dimensional page. It uses mathematicised recession to
construct a space, based on the notion that, to the naked eye, parallel lines
recede in space to a single point.
A specification is a written precise description which stipulates a technical standard for a material, product, method, or service. It a text but included as part of a drawing set for construction.

Types of Drawings
Floor Plan︎︎︎
Site Plan︎︎︎
Topographic / Landscape
Animated / Breakaway