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Search engine optimization:-
Search engine optimization (SEO) is the process of improving the
visibility of a website or a web page in search engines via the "natural"
or un-paid ("organic" or "algorithmic") search results. In general, the
earlier (or higher ranked on the search results page), and more frequently
a site appears in the search results list, the more visitors it will
receive from the search engine's users. SEO may target different kinds of
search, including image search, local search, video search, academic
search, news search and industry-specific vertical search engines.
As an Internet marketing strategy, SEO considers how search engines work,
what people search for, the actual search terms typed into search engines
and which search engines are preferred by their targeted audience.
Optimizing a website may involve editing its content and HTML and
associated coding to both increase its relevance to specific keywords and
to remove barriers to the indexing activities of search engines. Promoting
a site to increase the number of backlinks, or inbound links, is another
SEO tactic.
The acronym "SEOs" can refer to "search engine optimizers," a term adopted
by an industry of consultants who carry out optimization projects on
behalf of clients, and by employees who perform SEO services in-house.
Search engine optimizers may offer SEO as a stand-alone service or as a
part of a broader marketing campaign. Because effective SEO may require
changes to the HTML source code of a site and site content, SEO tactics
may be incorporated into website development and design. The term "search
engine friendly" may be used to describe website designs, menus, content
management systems, images, videos, shopping carts, and other elements
that have been optimized for the purpose of search engine exposure. |
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History:-
Webmasters and content providers began optimizing sites
for search engines in the mid-1990s, as the first search engines were
cataloging the early Web. Initially, all webmasters needed to do was
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, where a second program, known as an indexer,
extracts various information about the page, such as the words it contains
and where these are located, as well as any weight for specific words, and
all links the page contains, which are then placed into a scheduler for
crawling at a later date.
Site owners started to recognize the value of having their sites highly
ranked and visible in search engine results, creating an opportunity for
both white hat and black hat SEO practitioners. According to industry
analyst Danny Sullivan, the phrase "search engine optimization" probably
came into use in 1997. The first documented use of the term Search Engine
Optimization was John Audette and his company Multimedia Marketing Group
as documented by a web page from the MMG site from August, 1997.
Early versions of search algorithms relied on webmaster-provided
information such as the keyword meta tag, or index files in engines like
ALIWEB. Meta tags provide a guide to each page's content. Using meta data
to index pages was found to be less than reliable, however, because the
webmaster's choice of keywords in the meta tag could potentially be an
inaccurate representation of the site's actual content. Inaccurate,
incomplete, and inconsistent data in meta tags could and did cause pages
to rank for irrelevant searches. Web content providers also manipulated a
number of attributes within the HTML source of a page in an attempt to
rank well in search engines.
By relying so much on factors such as keyword density which were
exclusively within a webmaster's control, early search engines suffered
from abuse and ranking manipulation. To provide better results to their
users, search engines had to adapt to ensure their results pages showed
the most relevant search results, rather than unrelated pages stuffed with
numerous keywords by unscrupulous webmasters. Since the success and
popularity of a search engine is determined by its ability to produce the
most relevant results to any given search, allowing those results to be
false would turn users to find other search sources. Search engines
responded by developing more complex ranking algorithms, taking into
account additional factors that were more difficult for webmasters to
manipulate.[original research?]
Graduate students at Stanford University, Larry Page and Sergey Brin,
developed "backrub," a search engine that relied on a mathematical
algorithm to rate the prominence of web pages. The number calculated by
the algorithm, PageRank, is a function of the quantity and strength of
inbound links. PageRank estimates the likelihood that a given page will be
reached by a web user who randomly surfs the web, and follows links from
one page to another. In effect, this means that some links are stronger
than others, as a higher PageRank page is more likely to be reached by the
random surfer.
Page and Brin founded Google in 1998. Google attracted a loyal following
among the growing number of Internet users, who liked its simple design.
Off-page factors (such as PageRank and hyperlink analysis) were considered
as well as on-page factors (such as keyword frequency, meta tags,
headings, links and site structure) to enable Google to avoid the kind of
manipulation seen in search engines that only considered on-page factors
for their rankings. Although PageRank was more difficult to game,
webmasters had already developed link building tools and schemes to
influence the Inktomi search engine, and these methods proved similarly
applicable to gaming PageRank. Many sites focused on exchanging, buying,
and selling links, often on a massive scale. Some of these schemes, or
link farms, involved the creation of thousands of sites for the sole
purpose of link spamming.
By 2004, search engines had incorporated a wide range of undisclosed
factors in their ranking algorithms to reduce the impact of link
manipulation. Google says it ranks sites using more than 200 different
signals. The leading search engines, Google, Bing, and Yahoo, do not
disclose the algorithms they use to rank pages. SEO service providers,
such as Rand Fishkin, Barry Schwartz, Aaron Wall and Jill Whalen, have
studied different approaches to search engine optimization, and have
published their opinions in online forums and blogs. SEO practitioners may
also study patents held by various search engines to gain insight into the
algorithms.
In 2005, Google began personalizing search results for each user.
Depending on their history of previous searches, Google crafted results
for logged in users. In 2008, Bruce Clay said that "ranking is dead"
because of personalized search. It would become meaningless to discuss how
a website ranked, because its rank would potentially be different for each
user and each search.
In 2007, Google announced a campaign against paid links that transfer
PageRank. On June 15, 2009, Google disclosed that they had taken measures
to mitigate the effects of PageRank sculpting by use of the nofollow
attribute on links. Matt Cutts, a well-known software engineer at Google,
announced that Google Bot would no longer treat nofollowed links in the
same way, in order to prevent SEO service providers from using nofollow
for PageRank sculpting. As a result of this change the usage of nofollow
leads to evaporation of pagerank. In order to avoid the above, SEO
engineers developed alternative techniques that replace nofollowed tags
with obfuscated Javascript and thus permit PageRank sculpting.
Additionally several solutions have been suggested that include the usage
of iframes, Flash and Javascript.
In December 2009, Google announced it would be using the web search
history of all its users in order to populate search results.
Google Instant, real-time-search, was introduced in late 2009 in an
attempt to make search results more timely and relevant. Historically site
administrators have spent months or even years optimizing a website to
increase search rankings. With the growth in popularity of social media
sites and blogs the leading engines made changes to their algorithms to
allow fresh content to rank quickly within the search results. |
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