Search engine optimization (SEO) is a set of methodologies aimed at improving the visibility of a website in search engine listings. The term also refers to an industry of consultants that carry out optimization projects on behalf of client sites. The process of improving web pages so that it ranks higher in search engine for targeted keywords with the ultimate goal of generating more revenue from the web site. There are many SEO techniques. In general, these techniques can be categorized as On-Page Optimization, On-Site Optimization, and Off-Site Optimization. Designing a website so that it ranks highly in the search engines when someone searches for specific phrases related to the site.
SEO is the set of practices aimed at ensuring that your website ranks higher in search engine results. Activities include backlinking, meta tag optimization and robots.txt file.
Search engine optimization means optimizing a site to rank in search engine so that the site will be given a chance to find by user.
A method used in search engine marketing wherein SEO specialists helps the site become popular in Search engines, as well as its rankings.
what do you mean? SEO is the ways to increase your rank in search engine(like google, yahoo, etc.). To do it, you need to optimize keywords, add backlinks, etc. Not a software..but you can use a SEO service if you want to. But myself will never use that kinds of service, seems useless...
This is just the tactics to promote the online visibality of a web page or site by a perticuler search term.
Some SEO uses tools from the internet which does not require any installation. These are, live PR checker from different DCs, wordtracker, Adwords keyword ideas, and many more. For some SEOs, they use Google toolbar.