SEO: stands for Search Engine Optimization - Search engine optimization by optimizing Onpage and offpage aims to bring your website to the highest ranking on the natural result area of Search engine like Google, Yahoo. Bing. The goal of SEO is to put your site on top of the search results by a specific keyword (keywword). For example, an SEO services company wants the keywords "SEO services, cheap SEO services, SEO services, TOP 10 google.com, they need to do SEO to TOP with words lock that.
+ SEM: SEM = SEO + ADWORDS + LBS + VSM. As such, SEM is a broader concept and includes SEO in it. In other words, SEO is a branch of SEM. SEM is the synthesis of various marketing methods aimed at helping your website stand as you would like in internet search results.