In logo design, there are several different types of logos that designers and their clients refer to in order to get a rough idea of the look of a logo. The abstract mark, in logo design, is one of the most widely used types and, as the name suggests, refers to a pictorial mark that doesn't directly represent something in the real world. The most famous and clear example of an abstract mark is the Nike swoosh. While an abstract mark may well have a hidden meaning behind it, like the Nike swoosh being representative of the wing of the goddess "Nike", it isn't a symbol of a wing. Abstract marks are often used by globally known corporations as the mark is easily recognizable while it also doesn't need to be localized for different languages.
Some famous examples of abstract marks include the logos of: