Search engine optimization (SEO) is the process of improving the visibility of a website or a web page in search engines via the "natural" or un-paid ("organic" or "algorithmic") search results. wikipedia.org

Email marketing is directly marketing a commercial message to a group of people using electronic mail email. wikipedia.org

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

"Google Tag Manager makes it easy for marketers to add and update website tags, including analytics, remarketing, and more, with just a few clicks." wikipedia.org

Web analytics is the measurement, collection, analysis and reporting of web data for purposes of understanding and optimizing web usage.

Analytics is the discovery and communication of meaningful patterns in data. Especially valuable in areas rich with recorded information, analytics relies on the simultaneous application of statistics, computer programming and operations research to quantify performance. wikipedia.org

Google AdWords is Google's main advertising product and main source of revenue. wikipedia.org

An SEO audit is an assessment to determine whether or not adjustments need to be made to a site from SEO perspective.

Customer relationship management (CRM) is a widely implemented strategy for managing a company's interactions with customers, clients and sales prospects. wikipedia.org

Affiliate marketing is a marketing practice in which a business rewards one or more affiliates for each visitor or customer brought about by the affiliate's own marketing efforts. wikipedia.org

Business intelligence (BI) mainly refers to computer-based techniques used in identifying, extracting, and analyzing business data, such as sales revenue by products and/or departments, or by associated costs and incomes. wikipedia.org