Simplicity is a condition characterized by the fact that only a few factors contribute to its emergence or existence, and by the fact that the interaction of these factors can be described by only a few rules.

Simplicity is the opposite of complexity. In scientific logic, the principle is to explain a given fact with as few elements as possible, thus avoiding unnecessarily complex causal chains as much as possible.

On the other hand, simplification can also lead to misconceptions of facts, which is why it can also be used manipulatively or for propaganda purposes. Simplification can also have didactic reasons to facilitate understanding.

Simplicity is considered desirable when as much as possible can be achieved with as few means as possible. Then it is a synonym for minimalism and clarity.

Ancient natural philosophers demanded that a true theory should not only be beautiful (in the sense of a logical, coherent structure) and good (i.e. functional and concretely realizable), but also simple. Albert Einstein also held this view.

From Wikipedia