When building a website, cross-browser compatibility is a crucial factor that affects your site's performance and user experience. This term refers to the ability of web applications to function correctly across various web browsers, such as Chrome, Firefox, Safari, and Edge. To ensure your website is accessible and performs well for all users, it's essential to understand the differences in how these browsers interpret code and render content. For beginners, key aspects to focus on include HTML, CSS, and JavaScript compatibility, as well as responsive design techniques.

To achieve cross-browser compatibility, developers often follow a set of best practices, including:

1. Testing your website on multiple browsers and devices.
2. Utilizing web standards such as W3C specifications.
3. Using CSS resets to mitigate browser default styles.
4. Implementing feature detection using tools like Modernizr.

Cross-browser compatibility is essential for delivering a seamless user experience across different web browsers. Here are the top 10 best practices to help you tame cross-browser issues:

1. Use a CSS Reset: Applying a CSS reset can eliminate default styling discrepancies, creating a consistent baseline for your design.
2. Leverage Feature Detection: Utilize libraries like Modernizr to detect browser capabilities rather than relying solely on browser sniffing.
3. Test Early and Often: Conduct testing on actual devices and popular browsers throughout the development process to catch issues early.
4. Validate Code: Ensure your HTML and CSS code is valid using validators to minimize unexpected behaviors across different browsers.
5. Utilize Cross-Browser Libraries: Implement libraries like jQuery to simplify the handling of compatibility issues without sacrificing functionality.

Continuing with the best practices, here are the final five tips to consider:

6. Consistent Use of Vendor Prefixes: Use tools like Autoprefixer to automatically insert vendor prefixes in CSS for better support across various browsers.
7. Minimize the Use of Browser-Specific Features: Avoid using features exclusive to one browser; instead, opt for standardized solutions that work across multiple platforms.
8. Keep Up with Updates: Stay informed about browser updates and changes in web standards to adapt your site promptly.
9. Consider Responsive Design: Implement a responsive design approach to ensure your site adapts well to different screen sizes and resolutions.
10. Document Your Findings: Keep records of any cross-browser issues and solutions you've encountered to streamline future projects.

When it comes to website design, one common issue that webmasters encounter is why their website is displaying differently across browsers. This inconsistency can be attributed to various factors, including differences in browser rendering engines, CSS compatibility, and JavaScript support. Each browser, such as Chrome, Firefox, Safari, and Edge, processes HTML, CSS, and JavaScript code in slightly different ways, which can lead to unforeseen discrepancies in layout and functionality.

Another significant reason for varying website displays is the use of vendor prefixes in CSS and outdated browser versions. If your website relies on specific CSS properties that are not widely supported, it may render differently across browsers. Additionally, not everyone updates their browser regularly, resulting in users viewing a version of your website that does not meet current web standards. To ensure a consistent user experience, it's crucial to test your website across multiple browsers and use responsive design techniques where possible.