HTML5 refers to the markup language and core technology that is used for both creating and displaying content across the internet. The HTML standard was created in 1990, and HTML5 is the fifth revision of that standard. The goal of HTML5 is improvement of the language through the most advanced multimedia support. With this revision, HTML5 seeks to remain easy to read and understand by humans, computers, and devices even as it is updated. HTML5 includes HTML4 as well as XHTML1 and DOM Level 2 HTML.

HTML5 also has the goal of becoming an all-encompassing markup language for the web rather than allowing the continuance of multiple languages. HTML5 can be written in the syntax of either HTML or XHTML. Furthermore, HTML5 consists of models for detailed processing that support implementations that are more interoperable in nature. HTML5 also brings markup and APIs (application programming interfaces) to complicated web applications, and it creates a more cohesive system for the markup language that is used across the web. Finally, HTML5 has developed new syntax for this markup language and it seeks to more easily correct errors in syntax across the web.

Because of its comprehensive nature, HTML5 has the potential to be used in the design and development of cross-platform mobile applications, which refers to mobile apps that function on multiple operating systems and devices. HTML5 was designed to work on mobile devices as well as desktop devices, also making it very beneficial for the development of cross-platform mobile apps.