What is difference between continent and sub continent?

a continent is a large landmass which is ideally separated by large expanse of water..it has distinct features like mountains,valleys, plains, plateaus, deserts,climatic conditions etc and is composed of countries..

but a subcontinent is a large landmass which is inside a continent but having the special distinctive feature of that of a continent like mountain ranges that separate it from the rest of the continent,sea surrounding it,plateaus,plains,deserts and most importantly varied climatic conditions on different parts of it..

a subcontinent has every feature to be called as a continent except that it is not large enough to be called a continent