External Link:
i. Establish link with an external web page in known as external linking.
ii. It is made possible by providing the URL of the external file in the HREF attribute of < A > tag of the current page.

i) Definition list is surrounded within < DL > ........ </DL> tags.
ii) Definition term is presented in between < DT > ..... < /DT > tag and
iii) Definition description should be surrounded within < DO > < /DD > tag.

The general syntax of < hr > tag with attributes:
< hr size=value width=value noshade, color=color _name/code >

A list block can be defined inside another list is called as nested list.

Paragraphs can be centered with Align attribute with < p > tag. But for non-paragraph text contents can be centered with < center > tag. The < center > tag is used to centralize a segment of text.
What we type between < center > and < /center > will be displayed in the center of the browser.
< html >
< head >
< title > Center the text < /title >
< /head >
< body >
< hi align = center > Thiruvallur < /hi > < center > Thiruvallur was originally known as Thiruvallur which specifies the sleeping position of the holy lord < b > "Balaji" < b >, in the < b > < u > Veeraragava swamy temple of Thiruvallur. < /b > < Iu > < /center >
< /body >
< /html >

Multiple fonts with face attribute:
The face attribute of font tag ·is used to change font style of a segment of text. In face attribute, we can assign more than one font-name at a time within double quotes with comma. For example,
< font face = "Bookman old style!, Broadway!, Forte, Arial" >
Welcome to HTML
< /font >
Browser first tries to find out whether the font-name in the list is supported or not. If the first font is not supported by the browser, then it displays the text in second font, otherwise it will display next one. If no font in the list is supported, then the browser display the in the default font.

Highlighting text :
Highlighting is an important formatting feature is used to call attention to the reader. The < mark > tag is used to highlight the text in HTML. This is also a container tag. Whatever the text given between < mark > and < /mark > will be displayed as highlighting with default color.
HTML CODE:
< html >
< head >
< title > Highlighting text < /title >
< /head >
< body >
A Computer is an < mark > electronic
< /mark > device
< /body >
< /html >

All tags which are in pair are called a container tags. All container tags required a closing tag. These tags are otherwise known as "Physical Style" tags.
Physical Style Tags

Attributes of Ordered List :
There are two attributes can be used to customize ordered list.
1. Type - Changing numbering style
2. Start - Changing numbering order.
Type - is used to change the number style. The default number style is standard Arabic numeral If (1,2,3 .....)

Start - is used to specify the number of letter with which start the list. The default starting point is 1. The value Of the start attribute should be a decimal number, regardless of the. numbering style being used.

(i) A Subscript is a way to display a character or a, number below the normal line of type. For example: The scientific notation for water is H₂O. It should be written as H₂O Here, 2 is appearing below the normal line. This is called subscript.
(ii) A Superscript is also a way to show a character or a number above the normal line of type. For example: The familiar algebra equation "a plus b the whole square" should be written as (a+b)² Here, the square value 2 is appearing above the normal line. This is called superscript.

Subscript and Superscript:
A Subscript is a way to display a character or a number below the normal line of type. For example: The scientiftc notation for water is H₂O. It should be written as H₂O. Here, 2 is appearing below the normal line. This is called subscript.
A Superscript is also a way to show a character or a number above the normal line of type. For example: The familiar algebra equation "a plus b the whole square" should be written as (a+b)². Here, the square value 2 is appearing above the normal line. This is called superscript.
Usually, the subscript and the superscript character or number is smaller than the rest of the text.
In HTML, the < sub > and < sup > tags are used to create subscript and superscripts respectively. The text or number given between < sub > and < /sub > will be displayed as subscript. Same as subscript, the text or number given between < sup > and < /sup > will be displayed as superscript.
HTML CODE:
< html >
< head >
< title > Subscript and Superscript
< /title >
< /head >
< body >
The scientific notation of Water is
H< sub > 2 < /sub > O < br >
(a+b) - < sup > 2 < /sup > = a< sup >2
< /sup > + 2ab + b-< sup >2 < /sup >
< /body >
< /html >

Attributes of < TD >, < TH > and < TR > tags:
(i) Align: Used to specify the horizontal alignment, of content within a cell. Left is the default alignment. Possible values are Right and Center.
(ii) VAlign: Used to specify the vertical alignment of the contents within a cell. Bottom is the default alignment. Possible values are Top and Middle
(iii) Width: Used to specify the width of a cell in terms of pixels or percentage.
(iv) BGcolor and Background: Bgcolor attribute is used to apply a particular colour to the background of a cell. Background attribute is used to apply an image or picture as the background of a cell.
(v) Rowspan and Colspan : Rowspan attribute is used to merge two or more cells in a row as a single cell. Colspan attribute is used to merge to two or more cells in a column as a single cell.
An HTML code to demon trate the attribute of < td > < th > and < td > tags:
< htrnl >
< head >
< title > Attributes of td, tr and th tags
< /title >
< /head >
< body >
< table border align=center >
< Caption > Govt. Hr. Sec. School, Mullai Nagar, Thiruvallur
< tr >
< th colspan=S > Boys and Girls
Strength during 2016-17 and 2017- 18 < /th >
< /ts>
< tr align=center >
< th rowspan=2 > Class < /th >
< th rowspan=2 > Group < /th >
< th colspan=Z bgcolor=silver >
2016 - 17 < /th >
2017 - 18 < /th >
< /tr >
< tr >
< th bgcolor=yellow> Boys < /th >
< th bgcolor=pink > Girls < /th >
< th bqcolor=yellow > Boys < /th >
< th bgcolor=pink> Girls < /th >
< tts >
< tr align=center >
< th rowspan=2 > XI < /th >
< th > Science < /th >
< td > 75 < /td >
< td > 82 < /td > 
< td > 65< /td >
< td > 96 < /td >
< /tr >
< tr align=center >
< th > Commerce < /th >
< td > 125 < ztd >
< td > 147 < /td >
< td > 118 < /td >
< td > 163 < /td >
<\trl >
< tr align=center >
< th rowspan=2 > XII < /th >
< th > science < /th >
< td > 86< /td >
< td > 97 < /td >
< td > 71 < /td >
< td > 106 < /td >
< \trl >
< tr align=center>
< th > Commerce < /th >
< td > 145
< td > 186
< td > 130
< td > 198
< /trl > 
< /table >
< /body >
< /html >