ID vs. Class in CSS: When to Use Which?

Understanding the Distinction Between ID and Class in CSS

In CSS, both ID and class play crucial roles in styling HTML elements. While they may seem similar, there are fundamental differences between their usage.

Defining the Differences

• ID (Identifier): An ID is unique within a document. It allows you to target and style a specific element with unmatched precision.
• Class: Unlike IDs, classes can be applied to multiple elements throughout a document. They provide a way to style elements that share common characteristics or styles.

When to Use ID and Class

ID: Use an ID when you need to:

• Style a single, unique element in the document, such as the main content or sidebar.
• Specify an individual target for specific actions like navigation links or form submission.

Class: Employ classes when you want to:

• Apply the same styles to multiple elements with similar functionality or presentation.
• Define styles for elements that are not necessarily unique, such as headings, paragraphs, or list items.
• Create reusable styles that can be easily applied to different elements as needed.

Example Usage

Consider the following code:

#main-content {
  width: 80%;
  background-color: #ccc;
}

.sidebar-item {
  display: flex;
  justify-content: space-between;
}

<div>

In this example, the #main-content ID is applied to a single element, identifying it uniquely. On the other hand, the .sidebar-item class is used to style multiple sidebar items.

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