Initialism of search engine optimization.
"The company hired an expert to improve their seo and climb higher on Google's results page."
In plain English: SEO is the process of tweaking your website so it shows up higher on Google search results without paying for ads.
"The marketing team decided to hire an expert in seo to improve their website ranking."
A Korean surname, from Korean.
"Seo is a common Korean surname found in many families across the country."
The word SEO comes from the Korean surname Seo, which is cognate with the Chinese name Xu. It entered English as a common abbreviation for search engine optimization rather than retaining its original meaning as a family name.