A website should be search engine friendly by optimizing your webpage which includes meta tags, h1 tags, alt image tags, url optimization, unique and fresh content, internal linking, flash pages.

Also search engine friendly means you have to check canonical issue, broken links, speed, weight and so many other factors.

different search engine have different guideline on indexing and caching different type of  websites and each have restriction in indexing certain things. while developing website, you should follow those rules and make sure any element in design doesn't violet that rules as you want your website perform well in search engine.

SEO friendly website means the website is with simple functionality and more user friendly because Google always like to the user friendly websites on results.

Whenever one site called search engine friendly means that site was liked by search engines.
If you want your site should be search engine friendly then follow the steps
1. your site must having good design
2.Good content
3.No breaking URL's
4.higher the loading speed means within seconds.
etc..........

Of course, as we are dependent on search engines so we should create our website seo friendly.

thnks

This is a very common terms used in search engine optimisation, which is used describe a site that has specific elements added or modified to attract and please search engine spiders or Google Yahoo Bing crawlers. A website is called search engine friendly when its meta tags (title, description, keywords tags), body section, H1-H6, alt and title attributes are properly configured to make it search engine friendly and proper use of text as well.

SEO friendly website means the website is with simple functionality and more user friendly because Google always like to the user friendly websites on results.

I think a site which is easily crawled by search engine's crawlers is called search engine friendly site.