Types of OPTIMIZATION?

There are two types of Optimization:-
(1)OFF PAGE 
(2)ON PAGE

OFF PAGE also consists of following:-
(a)Directory submission
(b)Article submission
(c)Social bookmarking
(d)Forum posting
(e)Blog posting
(f)Press release submission
(g)Local/Global classified add and so on.

ON PAGE consists:-
(a)Keyword research and analysis.
(b)Doc-type analysis.
(c)Optimization of title tags for all important pages.
(d)Optimization of other meta tags.
(e)Optimization of header tags such as H1,H2,H3 etc
(f)Sitemap submission(XML/TEXT format).
(g)Optimization of HTML source code and so on

what is "BOT"?

Build Operate Transfer or Build Own Operate Transfer(BOOT) are software application that run automated tasks over the internet.
     "GOOGLE BOT" is an search bot software used by google which collects documents from the web to build  searchable index for the google search engine.It is also known as web crawling bot(sometimes also known as "SPIDER").

what is "SPIDER"?

"SPIDER" is a program that visit websites,read their pages and other information in-order to create entries for search engine index.
                 All the major search engines on the web consists of such program which is also known as "CRAWLER" and "BOT".
Example:-Google uses their own spider known as "GOOGLE BOT".

What is SEO?

SEO stands for "Search Engine Optimization".It is the process of increasing the amount of visitors to a website by obtaining a high-ranking in the search result page of a search engine.SEO is simply a matter of making sure your site is structured in a way that search engine understands.
                          Inshort it is a process of making a website or webpage more visible in the search engine such as google,bing and yahoo etc.