Every web developer (born before the year 2000) has heard of and has likely used the TABLE tag. Where did this come from? Well, a long time ago, in a galaxy far, far away, a team of alien programmers invented HTML table tags. These aliens soon grew weary of using this layout technique, so they banned its use and banished all the web development books that taught table tags their planet. Meanwhile, somewhere on Earth, circa 1994, a web developer who was frustrated with layout issues was hit on the head with what seemed like a technical book. Its markings appeared to be some form of hieroglyphics—all indecipherable to the young techie, except the distinctly familiar markup language. The first chapter's heading was simply, <TABLE>.

Kidding aside, while tables were tremendously helpful in the early days of web development, they are now an ancient layout technique that is often frowned upon. Here are some reasons why tables are no longer the default method for laying out page elements:

• They tend to clutter up the markup in our web pages and components 
• They are a maintenance nightmare, since moving things around is extremely tedious using tables
• They are rigid—more so than a grid, to the extent that we sometimes had to resort to having nested tables, which, of course, exacerbate the first two bullet points 

However, despite these negatives, using tables is still a valid option and is why I've listed it here as one of the main four.