What are the key differences between classes and IDs in CSS?

Key Differences Between Classes and IDs in CSS

In CSS, classes and IDs are used to apply styling to HTML elements, but there are some key differences between them:

1. Usage: Classes can be applied to multiple elements on a page, while IDs are unique and can only be used once per page. Classes are typically used for applying styles to a group of related elements, while IDs are used for styling a specific element.
2. Specificity: IDs have a higher specificity compared to classes. This means that styles applied using an ID will override styles applied using a class.
3. Selector Syntax: Classes are denoted by a period (.), while IDs are denoted by a hash (#) in CSS selectors. For example, to select a class named "example", you would use ".example", and to select an ID named "unique" you would use "#unique".
4. Performance: When it comes to performance, classes are generally more efficient than IDs. This is because browsers prioritize class selectors over ID selectors when applying styles, which can lead to faster rendering times.

It's important to use classes and IDs appropriately in your CSS to ensure a well-structured and maintainable codebase.