HTML Image
The <img> tag is empty, which means that it contains attributes only and it has no closing tag.
To display an image on a page, you need to use the src attribute. Src stands for "source". The value of the src attribute is the URL of the image you want to display on your page. The syntax of defining an image:
The URL points to the location where the image is stored. An image named "wap.gif" located in the directory "images" on "wapzero.mw.lt" has the URL: http://wapzero.mw.lt/img/wap.gif
The browser puts the image where the image tag occurs in the document. If you put an image tag between two paragraphs, the browser shows the first paragraph, then the image, and then the second paragraph.
The Alt Attribute
The alt attribute is used to define an "alternate text" for an image. The value of the alt attribute is an author-defined text:The "alt" attribute tells the reader what he or she is missing on a page if the browser can't load images. The browser will then display the alternate text instead of the image. It is a good practice to include the "alt" attribute for each image on a page, to improve the display and usefulness of your document for people who have text-only browsers.