What is the concept of inheritance in CSS?

Inheritance in CSS refers to the mechanism by which certain properties of a parent element are automatically passed down to its child elements. This means that when you set a style on a parent element, properties like font size, color, and certain other styling attributes can be applied to its child elements without needing to specify them again. This approach helps maintain a consistent look across a webpage and reduces redundancy in CSS code.

For instance, if you set a text color on a parent <div>, all child elements, such as <p> or <h1>, will inherit that text color unless otherwise specified. This cascading nature of CSS is foundational to how styles are organized and applied, allowing for a hierarchical structure in styling.

The other options do not accurately reflect how CSS inheritance works. While it's true that not all properties are inherited, and certain properties can be explicitly defined at the child level, the essence of inheritance lies in the fact that many properties do flow down from parent to child, creating an effective and systematic styling approach.