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◦To build User Interface:
◦To allow users to interact with web. Whatever we deliver
to the users is a combination of three technologies :
1. HTML for Structure(tells the different parts of content
and how they are related)
2. CSS for Presentation(tells how the content should be
displayed and formatted)
3. JavaScript for Behavior(tells how the content reacts
and changes based on user interaction)

◦(each technolo gy should be used only for its intended
purpose)

Benefits of using Specified technology only
for the intended purposes:
 Accessibility(clean semantic HTML markup benefits
users that consume the net through non visual browsers
like screen readers.)
 Portability(drop in new style sheet and implement
changes OR we can also use same CSS for multiple
projects)
 Maintainability(make changes only in the CSS file
when content need not to be changed)
 Reduced latency(CSS files are usually same for all
pages of a project, need not to download them
repeatedly)

 HTML consists of a set of tags and rules for using those
tags in developing hypertext documents.
 HTML is a Formatting/Markup language, not a
programming language.
HTML Documents = Web Pages
 HTML documents describe web pages
 HTML documents contain HTML tags and plain text
 HTML documents are also called web pages

HTML Tags:
 HTML tags are keywords (tag names) surrounded by angle brackets like
<html>
 HTML tags normally come in pairs like

<b> (start tag) and </b> (end tag)
 First tag turns the action ON and second turns it OFF

HTML Elements:
 an HTML element is everything between the start tag and the end tag,
including the tags
HTML Attributes:
 HTML elements can have attributes
 Attributes provide additional information about an element
 Attributes are always specified in the start tag
 Attributes come in name/value pairs like: name="value"

 <!DOCTYPE> is used to tell the
document type i.e. version of HTML
used. It is not an HTML tag. It is an
information (a declaration) to the
browser about what version the HTML
is written in. By default it is Html 5.
 The <head> element is a container for
all the head elements like title, meta,
styles and scripts
 The text between <html> and
</html> describes the web page
 The text between <body> and
</body> is the visible page content
 The text between <h1> and </h1> is
displayed as a heading
 The text between <p> and </p> is
displayed as a paragraph

 Headlines:  Lists:
<h1></h1>,<h2></h2>,…<h6></h6 There are three types of lists, ordered
> lists, unordered lists & definition lists.
H1 headings should be used as main Ordered:
headings, followed by H2 headings, then
1. Apple
the less important H3 headings, and so on.
2. Mango
 Paragraphs: Unordered:
HTML documents are divided into
 Apple
paragraphs.
 Mango
<p>……….. Text ………….</p>
Definition :
 Anchor:
Apple
<a href="url">Link text</a>
- is red in color
The <a> tag can be used in two ways:
Mango
 To create a link to another document,
by using the href attribute - is yellow in color
 To create a bookmark inside a
document, by using the name attribute

 Tables:  Div:
A table is divided into rows (with the <tr> tag), and
 The <div> tag defines a division or
each row is divided into data cells (with the <td>
a section in an HTML document.
tag). td stands for "table data," and holds the content
of a data cell. A <td> tag can contain text, links,  The <div> tag is used to group
images, lists, forms, other tables, etc. Header block-elements to format them
information in a table are defined with the <th> tag. with styles.
Example:

 Each division in this page is made
with the help of <div> tag .

 HTML web forms are a composition of
buttons, checkboxes, and text input
fields embedded inside of HTML
documents with one goal in mind: to
capture user input. By doing things
such as providing fields for user data
such as names, phone number, and
email addresses, web forms give users
the opportunity to interact directly
with a webpage.
 HTML forms are placed on a web page
using the <form> tag. This tag should
encapsulate a series of other form
elements, identifying them as a single
cohesive web form.
 HTML form elements rely on action
and method attributes to identify
where to send the form data for
processing (action) and how to
process the data (method).

 CSS stands for Cascading
Style Sheets
 In addition to setting a style for a
 Styles define how to display HTML element, CSS allows us to
HTML element i.e. it specify our own selectors called "id"
describes the presentation and "class".
semantics.
 A CSS rule has two main
 The id selector is used to specify a
parts:
style for a single, unique element. It
 a selector uses the id attribute of the HTML
 one or more declarations element, and is defined with a "#".

 The class selector is used to specify
a style for a group of elements.
Unlike the id selector, the class
selector is most often used on
several elements. It uses the HTML
class attribute, and is defined with
a "."

 id selector(#)
#para1
Each definition contains: {
text-align:center;
A property color:red;
}
A colon The style rule below will be
A value applied to the element with
A semicolon id="para1“
Eg: h1 {font-size:12pt; color:red}  Class selector(.)
.center { text-align:center; }
all HTML elements with
class="center" will be center-
aligned:

 Dominating effects of properties defined on
elements works on the specificity.
 There are rules to determine specificity.
 Briefly it works on point system:
 An element is worth=1 point
 A class is worth =10 points
 An id is worth =100 points
Eg:
 p a { } =2 points

 p.intro a { } =12 points

 #about p.intro a { }=112 points

 Inline style
 Internal style sheet
2. Embedded or internal styles
 External style sheet  A style is applied to the entire HTML file.
 Use it when you need to modify all
instances of particular element (e.g., h1)
in a web page
1. Inline styles Example:
 Add styles to each tag within the HTML <head>
file. <title>Getting Started</title>
 Use it when you need to format just a <style type=“text/css”>
single section in a web page.
h1 {font-family: sans-serif; color: orange}
Example:
</style>
<h1 style=“color:red; font-family: sans-
</head>
sarif”>
Inline style
</h1>

3. External style sheets
• An external style sheet is a text file containing the style definition (declaration)
• Use it when you need to control the style for an entire web site
 Example:

.html file abc.css

<head> h1 {font-family: sans-serif; color:
orange}
<title>Getting Started</title>
b {color: blue}
<link href=“abc.css”
rel=“stylesheet” type=“text/css”
/>
</head>

 In CSS, the term "box model" is used
when talking about design and  Margin - Clears an area around
layout. the border. The margin does
not have a background color, it
 The CSS box model is essentially a is completely transparent
box that wraps around HTML
elements, and it consists of:  Border - A border that goes
margins, borders, padding, and the around the padding and
actual content. content. The border is affected
by the background color of the
box
 Padding - Clears an area
around the content. The
padding is affected by the
background color of the box
 Content - The content of the
box, where text and images
appear

 A block element is an element that takes up the full width
available, and has a line break before and after it.
 Examples of block elements:
 <h1>
 <p>
 <div>
 An inline element only takes up as much width as necessary, and
does not force line breaks.
 Examples of inline elements:
 <span>
 <a>

We can change the block to inline and vice-versa:
Eg: p { display:inline; }

 Elements are floated horizontally, this means that an element can
only be floated left or right, not up or down.
 A floated element will move as far to the left or right as it can.
Usually this means all the way to the left or right of the containing
element.
 The elements after the floating element will flow around it.
 The elements before the floating element will not be affected.
 If an image is floated to the right, a following text flows around it,
to the left:
Eg:
img
{
float:right;
}

 The CSS positioning properties allow us to position an element.

1. Static Positioning (The default positioning for all elements is
position:static, which means the element is not positioned and
occurs where it normally would in the document.)
2. Relative Positioning (If we specify position:relative, then we can
use top or bottom, and left or right to move the element relative to
where it would normally occur in the document.)
3. Absolute Positioning (When we specify position:absolute, the
element is removed from the document and placed exactly where we
tell it to go.)
4. Fixed Positioning (An element with fixed position is positioned
relative to the browser window. It will not move even if the window is
scrolled)

 CSS pseudo-classes are used to add special effects to some
selectors.
selector:pseudo-class { property:value; }
Eg:
a:link {color:RED;} /* unvisited link */
a:visited {color:YELLOW;} /* visited link */
a:hover {color:GREEN;} /* mouse over link */
a:active {color:BLUE;} /* selected link */

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Html n CSS

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