Query strings are a way to pass information between web pages and applications, often used for filtering, searching, or customizing the user experience. By extracting data from query strings, web applications can adjust their behavior based on user input or other contextual information provided via the URL.

Example

Let's consider a simple URL example with a query string:

In this URL:

• The base URL is https://example.com/products;
• The query string begins with a question mark ?;
• There are two parameters, category and price;
• The values associated with these parameters are electronics and 100.

When a user accesses this URL, the web application can read and interpret the query string. For instance, it could filter products by "electronics" category and display items priced at or below $100. This enables users to access specific content or custom views of a website directly.