Design Theory
Gestalt Principles
The Gestalt Principles are a set of laws arising from 1920s’ psychology, describing how humans typically see objects by grouping similar elements, recognising patterns and simplifying complex images. Designers use these to engage users via powerful -yet natural- “tricks” of perspective and best practice design standards.
https://www.interaction-design.org/literature/topics/gestalt-principles
Semiotics
Semiotics, also called semiology, the study of signs and sign-using behaviour. It was defined by one of its founders, the Swiss linguist Ferdinand de Saussure, as the study of “the life of signs within society.” Although the word was used in this sense in the 17th century by the English philosopher John Locke, the idea of semiotics as an interdisciplinary mode for examining phenomena in different fields emerged only in the late 19th and early 20th centuries with the independent work of Saussure and of the American philosopher Charles Sanders Peirce.
https://www.britannica.com/science/semiotics
Design movements
As a designer, inspiration can come from anywhere. But sometimes influences, attitudes and approaches converge to form a coherent movement that has a knock-on effect around the world.
There have been hundreds of art and design movements of different sizes and significance over the centuries – some centred on the style or approach of a particular collective of artists in a particular place, others spanning many creative disciplines, and much more organic in terms of interpretation.
Whether they happened 150 years ago or 30 years ago, the impact of many of these is still felt today – you may even have felt their influence without knowing it. These things often move in cycles, particularly with the contemporary trend for retro aesthetics. So a little knowledge of art history goes a long way.
https://www.creativebloq.com/inspiration/15-influential-art-and-design-movements-you-should-know