Thanks, it made sense..

The purpose of CSS is to separate layout from content and content containers.

The ability to have multiple separate style sheets, Inheritance, and defined order of precedence are what allow this separation.

There are priorities rules for CSS to use in web design. These priorities are as follows:

1) inline CSS - write in HTML tag (e.g. test)  which can overwrite all other css[2 and 3 priorities ] in that tag.

2) embedded CSS - write in same file but using style sheet tags.

- this can overwrite CSS of external files(3 priorities).

3) external CSS- write in external files (e.g. test.css). This is useful for better management of css coding.

.fontTest{font-size: 10px;}

But now a days there are many frameworks like Bootstrap, foundation etc. by which you will be able to do programming in CSS too using less, sass etc. frameworks. And these may have different rules.

Good luck

CSS is full of "gotchas", particularly how things cascade. The official specification regarding cascades and inheritance is here:

http://www.w3.org/TR/2011/REC-CSS2-20110607/cascade.html

Some things to be aware of are:

1). Inheritance in CSS is property specific. For example, the "color" property is inherited by default, whereas the "border" property is not. Either learn these by trial and error or look up the default inheritance for each property. See:

https://developer.mozilla.org/en-US/docs/Web/CSS/Reference

2). How a property is applied can be modified by the keywords: "inherit", "initial" and "unset". Try to avoid these where possible as they usually end up costing more time than they save. See:

https://developer.mozilla.org/en-US/docs/Web/CSS/inherit

https://developer.mozilla.org/en-US/docs/Web/CSS/initial

https://developer.mozilla.org/en-US/docs/Web/CSS/unset

3). Where two properties end up competing for the same node in the DOM, precedence is assigned based on the specificity of the selector. For example, p.name {} is more specific than p {} so p.name {} will override p {}. See: 

https://developer.mozilla.org/en-US/docs/Web/CSS/Specificity

4). Where two properties end up competing for the same node in the DOM and there is no difference in selector specificity, the winner is determined by the order of reading by the browser. The official spec calls for imported stylesheets to be read first (in the order imported), then tags in document order, then inline styles. See:

http://www.w3.org/TR/2011/REC-CSS2-20110607/cascade.html#cascading-order

5). Use of the "!important" qualifier causes all competing properties to be overridden (even inline styles). For a CSS beginner, it can be very tempting to use "!important" out of frustration. By all means use it when trying things out, but don't leave it in your final product. See:

https://developer.mozilla.org/en-US/docs/Web/CSS/Specificity

6): Be aware of "all:" being used with inheritance modifiers. Eg, "all:initial;". Again, this is one of those things that people tend to use out of frustration but often causes more trouble downstream. Best to track down what's actually going wrong and build a clean stylesheet rather than rely on overrides. See:

http://mcc.id.au/blog/2013/10/all-unset

Finally, I strongly recommend debugging CSS with something like Firefox Developer Edition. See:

https://www.mozilla.org/en-US/firefox/developer/

Open up the inspector and modify styles on the fly to see what happens. It will also show you exactly how styles are cascading and where overrides are coming from. This is the best way to learn while keeping MDN in the background for when you really get stuck.

Then when you encounter the worst part of CSS (the part I haven't even mentioned yet), which is cross-browser compatibility, consider throwing it all in the bin and making the move to Sass or LESS ;-) These frameworks take care of all the nonsense for you, regarding cross-browser consistency, while also providing some neat syntactic sugar.

I believe that the correct answer to your question is "yes"!

But, just to be sure, I will expand on it.  It can be confusing, especially when you look at a property (e.g., the colour of a piece of text) that can be defined in many elements.  Here is how you follow the 'cascading':

1. Start from the outermost element (i.e., the ) and identify the relevant style definitions in the . That is, look at all linked stylesheets and elements in the order in which they appear.  Remember that any new style definition replaces or extends previous definitions.

2. Repeat the operation while going through the hierarchy of elements that enclose the one you are interested in (e.g., the

with the piece of text).

It is the concept of going 'deeper' inside the enclosing elements that justifies the term 'cascading', as each new style definition is likely to represent a refinement, affecting a smaller subset of elements.

To explore the cascading nature of CSS build a simple set of container using block html tags such as and nested

s and then set the background attribute for each using the various mechanisms such as style attribute, style element, and external files.

Well, if you look at the HTML standard (http://www.w3.org/TR/html401/struct/text.html#h-9.3.1) you will read that "The P element represents a paragraph. It cannot contain block-level elements (including P itself)."

To avoid problems, I would make the test with s and s. That will work wih HTML4, HTML5, and XHTML.

It's basically a style element. In fact you de facto use css withing html for e.g. :