What is Search Engine Marketing (SEM)?

Sem (Search Engine Marketing) is SEM stands for Search Engine Marketing. In other words, it means “marketing via search engines”. Marketing or promoting your products or services via search engines can be done in two main ways. You either optimize your site so it appears at a high spot in organic search results or pays for the clicks directly, in which case your site is listed under the “sponsored listings” section.

From Simba’s SEO Dictionary