Search engine marketing, (SEM), is a form of Internet marketing that seeks to promote websites by increasing their visibility in search engine result pages (SERPs) through the use of paid placement, contextual advertising, and paid inclusion. wikipedia.org

"Marketing automation refers to software platforms and technologies designed for marketing departments and organizations to more effectively market on multiple channels online (such as email, social media, websites, etc.) and automate repetitive tasks. Marketing departments, consultants and part-time marketing employees benefit by specifying criteria and outcomes for tasks and processes which are then interpreted, stored and executed by software." wikipedia.org

YouTube is a video-sharing website on which users can upload, view and share videos. wikipedia.org