Html is used only for web based applications or for console applications also?
Html is not a programming language, you can not write any applications using only html at all.
Nope, HTML stands for Hyper Text Markup Language. it used for simple things like font color and size, background, and other visual aspects of a website. The furthest you could go with an HTML code is a simple website with basic depth and shapes. C++, Java, php, etc are needed to further make use of HTML.