ETYM Latin idea, Greek, from idein to see; akin to Eng. wit: cf. French idée. Related to Wit.
1. A personal view.
2. The content of cognition; the main thing one is thinking about; SYN. thought.
In philosophy, a term that has had a variety of technical usages; modern philosophers prefer more specific terms like “sense datum”, “image”, and “concept”. An innate idea is a concept not derived from experience.
Plato’s Ideas (also called Forms) were immaterial objects outside the mind, universals or essences existing objectively in nature. In later Greek and in medieval philosophy, ideas tended to be in the mind of God. Since the 17th century, “idea” has nearly always been used for something in or having reference to the mind. For Immanuel Kant, an idea was a representation of something that cannot be experienced. For G W F Hegel, the term meant something like the overall pattern or purpose in the universe.

Stands for International Data Encryption Algorithm, a block cipher encryption algorithm developed by Xuejia Lai and James Massey.
See: International Data Encryption Algorithm (IDEA)