WML is analogous to HTML in several ways because it is written in plain text format. However, because wireless devices are not the same in terms of display, processing power and button layout, some features are specific to devices that are incorporated in WML.

The following are some key features of WML as compared to HTML:

• WML is a markup language for small, wireless computing devices.
  
• In WML, variables can be defined that store data in string format. In HTML, variables cannot be stored.
  
• WML uses WML script for client-side scripting, which is stored in a separate file. HTML uses JavaScript.
• The supported image format for WML is WBMP. HTML supports JPEG, GIF and BMP.
  
• A micro-browser is used to run WML markup. A regular browser, such as Internet Explorer, Firefox or Chrome, is used to run HTML markup.
  
• WML follows XHTML specification and is therefore case sensitive. HTML is not case sensitive.
  
• WML has fewer tags compared to HTML.
  
• A deck is a set of WML cards. In HTML, a site is a set of HTML pages.
  

WML-equipped devices have the following characteristics:

• Display Size: Devices have a small screen size and low resolution; therefore WML has to be capable of rendering content regardless of display size.
• Input: Small computing devices do not have a mouse or pointer-based navigation devices. They may have a small numeric keypad or a QWERTY keypad based on whether the device is simple or sophisticated. WML has to be capable of obtaining necessary user input regardless of the limitations of the device.
• Processing: They have limited-capacity rechargeable batteries with a low-power CPU and low memory. WML browsers should act like thin clients and perform minimal processing on the device.
• Network Capabilities: Small computing devices have a low bandwidth and high network latency. WML has to ensure maximum efficiency in fetching requested Web pages from the server.