SEM refers to online marketing strategies such as paid ad placement, contextual advertising, and paid inclusion that persons and companies use to promote their products and services to web surfers.
How does SEM differ from Search Engine Optimization (SEO)?
SEO typically refers to only non-paid online marketing strategies, whereas SEM refers to both paid and non-paid online marketing strategies. SEO strategies include keyword research, content creation, search engine algorithm research, back link creation, and HTML coding. SEM strategies include paid ad placement, which is paying to place