Note that SEM, search engine marketing is the term that includes all the Digital Marketing tactics, whether it’s free or paid. The major goal of SEM is to boost the visibility of your website on search engines. Following this, SEO, search engine optimization and PPC, pay per click comes under SEM. SEM is the crucial part of all the marketing strategies. So, to have a successful website you need Penang SEO, PPC SEM and follow whatever tactics feel good to you for your site.