What Do You Mean By HTML and CSS?
Common HTML Terms
Creating HTML Document Structure
Common CSS Terms
Selectors
Referencing CSS
CSS Resets
Getting to Know HTML And Semantics Overview
Identifying Divisions and Spans
Using Text Based Element
Building Structure
Creating Hyperlinks
Getting to Know CSS :The Cascade
Calculating Specificity
Combining Selectors
Layering Styles With Multiple Classes
Common CSS Properties
CSS Aural Media/Style Sheets
CSS Pagination
CSS Overflow
CSS White Space
CSS Word Wrap
CSS Outline
CSS Visibility
CSS Counters
CSS Animation
CSS Transition
CSS Tooltips
CSS Tooltip Animation
CSS Arrow
CSS Flexbox
CSS Media Queries
CSS 2D Transforms
CSS 3D Transforms
How are Elements Displayed?
Display Property Controls And Box Model?
Working With Box Model
Width and Height
Margins and Padding
Borders, Individual Border Sides, Border Radius, Box Sizing, Content Box and Padding Box
Developer Tools
Removing Spaces between Inline-Block Elements
Positioning With Floats
Floats in Practice
Positioning With Inline-Block
Clearing and Containing Floats
Creating Reusable Layouts
Uniquely Positioning Layouts
Adding Colour To Text
Changing Font Properties
Font Family
Font Size, Font Style, Font Variant, Font Weight And Line Height
Shorthand Font Properties
Applying Text Properties
Text Properties All Together
Using Web-Safe Fonts
Including Citation And Quotes
Adding A Background Colour
Adding a Background Image and Background Repeat
Background Position and Shorthand Background Image Values
Designing Gradient Backgrounds
Changing the Direction of a Gradient Background
Using Multiple Background Images
Exploring New Background Properties
Unordered Lists
Ordered Lists
Description Lists
Nested Lists
List Item Styling
List Style Type Values
List Style Position Property
Adding Media And Adding Images
Sizing Images
Positioning Images, Inline Positioning Images, Blocking Positioning Images , Positioning Images Flush Left or Right
Adding Audio
Adding Videos
Adding Inline Frames
Semantically Identifying Figures And Captions
Building Forms And Initializing a Form
Text Fields And Text Areas
Multiple Choice Inputs And Menus
Form Buttons
Other Inputs
Organizing Form Element
Form And Input Attributes
Login Form Example
Organizing Data with Tables
Creating A Table
Table Header
Table Structure
Table Head, Body and Foot
Combining Multiple Cells
Table Borders
Table Striping
Aligning Text
Completely Styled Table
HTML Coding Practices
Use the Proper Document Structure
Keeping the Syntax Organized
Use Practical ID and Class Values
CSS Coding Practices
Write CSS Using Multiple Lines and Spaces
Use Proper Class Names
Build Proficient Selectors
Use Desired Classes When Needed
Use Shorthand Hexadecimal Color Values
Drop Units Zero Values
HTML abbr tag
HTML acronym tag (Not for HTML 5)
HTML area tag
HTML basefont tag
HTML blockquote tag
HTML datalist tag
HTML Description List
HTML ins tag
Marquee HTML Tag
HTML object tag
HTML picture tag
HTML SVG
To make your CSS to share words with HTML you must reference your CSS file inside HTML. One of the best technique to reference CSS is by summing up all styles in one single external stylesheet and then referencing it within the 
element present in the HTML file. If you are using a separate stylesheet, then you can utilize similar styles over a whole website and rapidly make changes sitewide.
To make a CSS stylesheet, open up a text editor and save it by the extension name as '.css'. Note that you should keep the CSS file in the same folder or subfolder containing your HTML file.
Inside the HTML file there is an element named as Inside it is the 
element which helps in establishing the relationship between the HTML and the CSS file. As we are linking our HTML file with the CSS file, thus, we need to use the ‘rel' attribute provided with the value as a stylesheet. A second attribute, i.e. the 'href' attribute, helps in identifying the location where the CSS file is situated.
If you want your CSS to work properly, the path given for the href attribute value must straightforwardly associate to where our CSS record is kept. In the above code, the main.css file is present in the same location where the HTML file is situated (root directory).
If you have saved your CSS file in subfolder or subdirectory, then the href attribute value requires to correspond to this way in like manner. Take an example, like, if your CSS file main.css is kept inside a subfolder with the name of stylesheets, the value of href attribute should be stylesheets/main.css.
Now our web page is coming to life. We have not gone too deep inside CSS, but still, you will be noticing that a few styles have default styles we haven't proclaimed inside our CSS. Here the browser itself is imposing the default values. But don't worry, we can overwrite these styles as per our requirement, and we can do that using CSS resets.
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