Content management gives clients access to their site to add news stories, images, and edit pages, without needing to understand code. It can do much more, with customisation. Since 2013 the focus has been on responsive, mobile-first websites.
SEO (Search Optimisation)
A website is worth nothing without visitors, and when I create a website I routinely add it to Webmaster tools from Google (now Search Console) and Bing, and specific directories where applicable. Drupal or WordPress content management then automatically updates your site index as you simply add or update content.
I regularly work with Facebook pages and groups, Twitter, Flickr, Pinterest and Instagram for clients. I also have created a number of email marketing campaigns for clients using MailChimp, an easy to use HTML email programme that is free to use for up to 2,000 subscribers.