Reading--Notes

CSS

You can control the size of an image using the width and height properties in CSS, just like you can for any other box
two common ways in which you can horizontally center an image:

On the containing element, you can use the text-align property with a value of center.
On the image itself, you can use the use the margin property and set the values of the left and right margins to auto.

The background-image property allows you to place an image behind any HTML element. This could be the entire page or just part of the page. By default, a background image will repeat to fill the entire box. The path to the image follows the letters url, and it is put inside parentheses and quotes.

see the example below :

repeat The background image is repeated both horizontally and vertically (the default way it is shown if the backgroundrepeat property isn’t used).
repeat-x The image is repeated horizontally only (as shown in the first example on the left).
repeat-y The image is repeated vertically only.
no-repeat The image is only shown once. The background-attachment property specifies whether a background image should stay in one position or move as the user scrolls up and down the page.

If you want to overlay text on a background image, the image must be low contrast in order for the text to be legible.

On-Page Techniques : On-page techniques are the methods you can use on your web pages to improve their rating in search engines. The main component of this is looking at keywords that people are likely to enter into a search engine if they wanted to find your site, and then including these in the text and HTML code for your site in order to help the search engines know that your site covers these topics.

Off-Page Techniques : Getting other sites to link to you is just as important as on-page techniques. Search engines help determine how to rank your site by looking at the number of other sites that link to yours. They are particularly interested in sites whose content is related to yours. For example, if you were running a website that sold fish bait, then a link from a hairdresser is not likely to be considered as relevant as one from an angling community.

Visits : This is the number of times people have come to your site. If someone is inactive on your site for 30 minutes and then looks at another page on your site, it will be counted as a new visit.
Unique Visits : This is the total number of people who have visited your site over the specified period. The number of unique visits will be lower than the number of visits if people have been returning to your site more than once in the defined period.
Page Views : The total number of pages all visitors have viewed on your site.
Pages per Visit : The average number of pages each visitor has looked at on your site per visit.

The video and audio elements allow us to embed video and audio into web pages see the examples below :