In the most basic terms, an “abstract” sketch is a simplified drawing representing a physical object or person. Only the essential shapes are drawn, either with lines or blocks of color.
Some artists make abstraction the final goal in their art. But I look at abstraction as just one tool along the way in my drawing process. It’s a means to an end, not the end product itself. Abstracting a subject, like a bowl of fruit or a person, can help you break down the seemingly complex forms into their simple constituent pieces. But if an abstraction… watch this video