When referring to code in HyperText Markup Language (HTML), an HTML grid can be used to describe one of three things. It can refer to a formatting element known as a table within an HTML document. It also is commonly used when talking about an HTML compliance grid, showing which HTML features are supported by which web browsers. More rarely, it can be used as a way to describe a particular type of layout style implementation called a grid bag layout, in which elements are located at specific spots on a grid, much like a table, although JavaScript® or another programming language is needed to generate the HTML code for an HTML grid layout.
One very frequent use of the term "HTML grid" is in reference to a feature compliance grid. This is a type of chart in which many specific elements of the HTML standard are listed on one side, while the various types of web browsers are listed on the other, and each cell of the table reveals whether the element or feature is supported by a specific browser. This type of HTML grid is often used by designers to find the most supported features that can be used safely on a web page so it renders properly, and it allows the designer to know which features to avoid.
An HTML grid layout, or a grid bag layout, is a type of generated formatting for different elements within an HTML document. It resembles an HTML table in some ways, because divided rows and columns are used to define areas or cells in which the elements will be placed. It is unlike a table, because it is more dynamic and can be structured procedurally, allowing whatever programming language is being used to manipulate aspects of the positioning for specific results. Another aspect of an HTML grid layout is that it can create formatting patterns that are fluid and will grow or shrink depending on the display resolution of the HTML document.
The use of a table within an HTML document also can be called an HTML grid. A table is an area that looks like a grid — with text, images or other elements inside of each cell in the grid — where they mostly can be treated as if they were block-level elements. The individual cells within an HTML table can have borders drawn around them, so the overall appearance of the final table is sometimes said to look like a grid, especially when the width and height of the cells are equal.