Search Engine Optimization (SEO) is the process of optimizing a website so that it performs well in organic search. Ranking high for search terms - keywords - increases the visibility of a website and leads to a higher number of visitors. Put more simply, SEO will allow you to connect with those searching for your product or service and help turn them into customers.
SEO is a combination of factors that help search engines find and trust you, organize the information you’re publishing, and present it to users searching for it. SEO isn’t a single tool or process, nor a series of tricks (like keyword stuffing) or secrets (like link trading) you can use to fool search engines. It’s also not a series of shortcuts that allow you to buy your way to the top of the search results.