I know this two programming language are ways to create website. Yet, I'm still confuse with the difference between the two. I would like also to know which is easier to do in creating website?
Neither of them are really programming languages. HTML is a mark-up language that describes the structure and content of a web page. CSS controls the appearance of the elements the page is built from. Both are required to make a webpage, unless you want a black and white, plain text webpage, in which case only HTML is required.
Below is a simplified answer, may not be 100% technically correct in terminology, but perhaps good enough to clarify your basic doubt:
HTML is the language, that can be used to format contents displayed in webpages and control their layout, look and feel, etc. In the starting phase of internet (very first websites), pages would be written only in HTML. Over a period of time, people realized that their are 4 key components in a webpage:
1) The content
2) The layout itself (defining various sections of the page)
3) Fine details about the look and feel of the layout (color, corner shapes, shading, and tons of other parameters)
4) Special effects - animations and much more
So typically, when you create a website, you will be using HTML & CSS both. You can avoid "much" of CSS by using old fashioned HTML code, but its highly recommended you keep the sectioning of the page in HTML and the look and feel in CSS for long term benefits.
A simpler way to look at this is:
HTML: defines the structure of the document.
CSS: defines the presentational styles.