What is SEO, and why should we care?

Mention SEO to a lot of people and be prepared to be met with a blank expression and a complete lack of interest. And yet, we as a society are becoming increasingly reliable on the internet; using it for everything from work, to satisfying our shopping needs and even down to planning that perfect holiday. So surely it would be advantageous and within people's interest to understand the fundamental ways in which the internet actually works?
This is where SEO comes in. For those who don't know, SEO stands for search engine optimisation and is essentially the practice of making websites as visible as possible in Google ranking systems, using a variety of tried and tested techniques, including link-building and keyword research.
This may seem like the terrain of geeks and IT experts alone, however the reality is that when SEO is done ethically, it actually improves the quality of what can be found on the internet, and of equal importance, it makes quality content that much easier to find.
Speaking as a recovering technophobe, even the most basic understanding of SEO can vastly improve a person's experience, expectation and ultimately their overall enjoyment of the internet. For example, if you think about your own internet habits then you'll know that it's very rare for people to look beyond the first three pages of search results.
Ethical SEO ensures that only the most authoritative websites, with regularly updated content, that is both high in quality and relevant to its particular area of expertise, are visible in the first few pages of search results. Thus making it much easier for even the most casual of internet users to find the information or product best suited to them in a fraction of the time.
The way in which this is achieved by Google is through a series of formulas called algorithms. These formulas basically dictate exactly how a website is ranked. It is the job of the SEO expert to study and test the search engine's system in order to distinguish these patterns in as accurate a way as possible. This could be described as a kind of battle of wits, with each party constantly second guessing one another, resulting in constant tweaks and updates to the algorithms.
It will be interesting to see if SEO continues to thrive, the way in which it is currently, and what lasting changes it will have on the internet. Meanwhile, I for one am grateful that there are people out there, 'manning the internet' as it were, improving its function for the rest of us. I have neither the time nor inclination to continue stumbling onto badly constructed websites, which are of absolutely no relevance to me, so if SEO can make those occurrences happen less frequently, then I say long may it reign.