The concept of browser compatibility refers to the ability of a website or web application to function properly across different web browsers and devices. Ensuring compatibility is important because users access content using various platforms, including Google Chrome, Safari, and Firefox. Inconsistencies may lead to a poor user experience, such as misaligned layouts or broken features. Developers use standards like HTML, CSS, and JavaScript to create responsive designs that adapt to various browsers. Addressing compatibility issues is crucial for ensuring accessibility and maximizing reach.