Webmasters and content providers began optimizing websites for search engines in the mid-1990s, as the first search engines were cataloging the early Web. Initially, all webmasters only needed to submit the address of a page, or URL, to the various engines which would send a "spider" to "crawl" that page, extract links to other pages from it, and return information found on the page to be indexed. The process involves a search engine spider downloading a page and storing it on the search engine's own server. A second program, known as an indexer, extracts information about the page, such as the words it contains, where they are located, and any weight for specific words, as well as all links the page contains. All of this information is then placed into a scheduler for crawling at a later date.
There were some great tips in this article. I notice that many people make the mistake of making too many distracting images in the header and the sidebar which can quickly turn people off content. I particularly dislike google ads anchored in the centre of a piece of text. I understand that people want to make a revenue for ads but there are right ways and wrong ways of going about this. The writing part of the content is the important part, why would you take a dump on it by pouring a load of conflicting media in the sides?
The leading search engines, such as Google, Bing and Yahoo!, use crawlers to find pages for their algorithmic search results. Pages that are linked from other search engine indexed pages do not need to be submitted because they are found automatically. The Yahoo! Directory and DMOZ, two major directories which closed in 2014 and 2017 respectively, both required manual submission and human editorial review. Google offers Google Search Console, for which an XML Sitemap feed can be created and submitted for free to ensure that all pages are found, especially pages that are not discoverable by automatically following links in addition to their URL submission console. Yahoo! formerly operated a paid submission service that guaranteed crawling for a cost per click; however, this practice was discontinued in 2009.