title: Cross-browser compatibility issues
body: <p>I see that many people have problems with cross-browser compatibility issues. </p>
  
  <p>My question is why do browsers render the html, css or js differently?</p>
  
  <p><strong>Is it due to the DOM? The box model?</strong></p>
  
  <p>Why are there cross-browser compatibility issues when there are standards from W3C etc?</p>
  
  <p><strong>Are there any differences in the way the major Internet browsers display HTML content? Why is it that Internet Explorer, Firefox (Mozilla), Opera may display the same content differently?</strong></p>
  
  <p><strong>What should I keep in mind when building a cross-browser compatible web site?</strong></p>