(i) GIF (Graphical Interchange Format) : This format is one of the popular format for animated images. It was developed by CompuServe. Usually this image format is suitable for presenting tiny animated images, logos, icons, line art etc., It is not suitable for photographic work, because it uses maximum of 256 colours. Animated GIF do not support sound or playback control.
(ii) JPEG (Joint Photographic Experts Group): JPEG is the most popular image format supported by all web browsers. This format is suitable for photographic images. Unlike GIF, JPEG can include any number of colours.
(iii) PNG (Portable Network Graphics): PNG is designed as a replacement for GIF. It is also Supported by all browsers.
(iv) SVG (Scalable Vector Graphics): SVG is a graphics format that was developed for web. It was standardized by world wide web consortiumn (W3C) in 2001. All current web browsers supports basic features of SVG.

In HTML, a piece of text or image can be moved horizontally or vertically by using < marquee > tag This feature makes a web page as more attractive.
General format:
< marquee >  Text or image to be scroll < /marquee > attributes of < marquee >
(i) Height and width: These attributes are used to set height and width of the marquee. The values should be either in pixels or in percentage the browser window.
(ii) Direction: This is used to specify the direction of the movement of text or image. The text or image will move towards right to left by default. So, the default direction is left. The Possible values are 'up'. 'down'. 'left' or 'right'.
(iii) Behaviour : This attribute is used to specify the type of scrolling. The values are 'scroll'. 'slide' and 'alternate'.
(iv) Scrolldelay : This attribute is used to define the time delay between each jump. The time unit -should be in seconds.

The important attributes used with the < form > tag are method and action attributes.
(i) Method : The method attribute of the form tag is used to identify how the form element names and values will be sent to the server. The get method will append the names of the form elements and their values to the URL. The post method will send the names and values of the form elements as packets.
(ii) Action: The action attribute identifies the server side program or script that will process the form. The action will be the name of a Common Gateway Interface (CGI) program written in programming languages, like Perl, JavaScript, PHP or Active Server Pages (ASP).
General Format of < form > tag
< Form method=get/post action= "back_end_server_script" >
Form elements
< /Form >

Value of type attribute	Description
Text	Create a Text Box. The element used to get all kind of text input such as name, address etc.,
Password	Similar as Text box. But, while entering data, the characters are appearing as coded symbols such as asterisk
Checkbox Multi select box	Check box is an element appearing like a small square box. When the user click on the square a tiny tick mark will appear inside the square. This element is used to select multiple options.
Radio Button	Radio button is used to select anyone of the multiple options from the list. This element looks like a small circle, when the user select an item, a tiny dot will appear within the circle. If the user selects another option, previously selected option will be deselected. This means, user can select anyone of the given option form a group
Reset	It is a special command button used to clear all the entries made in the form.
Submit	It is also a special command button used to submit all the entries made in the form to the backend server.
Button	This is a standard graphical button on the form used to call functions on click

Attributes of <Select> tag:
(i) The <select> tag is used to create dropdown list box in HTML.
(ii) It provides a list of various options as a dropdown list.
(iii) This element is more helpful when a number of options are to be displayed in a limited space.
(iv) The <option> tag is used to specify list items.
(v) Name - Provide the name to the control, which is sent to the server.
(vi) Size - Determine the style of dropdown list box.
Size = 1 dropdown list box.
Size =2 List box
(vii) Multiple - Allows user to select multiple values.
Attributes of <option> tag :
(i) Selected - Indicate default selection.
(ii) Value - Value to be submitted to server.