What is e-marketing /internet marketing/online marketing?
Internet marketing, also referred to as online marketing or Emarketing, is marketing that uses the Internet. The Internet has brought many unique benefits to marketing including low costs in distributing information and media to a global audience. The interactive nature of Internet media, both in terms of instant response, and in eliciting response at all, are both unique qualities of Internet marketing.
Internet marketing ties together creative and technical aspects of the internet, including design, development, advertising and sales. Internet marketing methods include search engine marketing, display advertising, e-mail marketing, affiliate marketing, interactive advertising and viral marketing.     

What is SEO? 
Search engine optimization (SEO) is the process of improving the volume and quality of traffic to a web site from search engines via "natural" ("organic" or "algorithmic") search results. Usually, the earlier a site is presented in the search results, or the higher it "ranks", the more searchers will visit that site. Click here for more info on SEO
 

How Does SEO work?
As a marketing strategy for increasing a site's relevance, SEO considers how search algorithms work and what people search for. SEO efforts may involve a site's coding, presentation, and structure, as well as fixing problems that could prevent search engine indexing programs from fully spidering a site. Other, more noticeable efforts may include adding unique content to a site, ensuring that content is easily indexed by search engine robots, and making the site more appealing to users.                 

What is Search Engine Marketing? 
Search Engine Marketing, or SEM, is a form of Internet Marketing that seeks to promote websites by increasing their visibility in the Search Engine results pages (SERPs). According to the Search Engine Marketing Professionals Organization, SEM methods include: Search Engine Optimization (or SEO), paid placement, and paid inclusion. Other sources, including the New York Times, define SEM as the practice of buying paid search listings with the goal of obtaining better free search listings

What is Email marketing? 
Email marketing is a form of direct marketing which uses electronic mail as a means of communicating commercial or fundraising messages to an audience. In its broadest sense, every email sent to a potential or current customer could be considered email marketing. However, the term is usually used to refer to:

• Sending emails with the purpose of enhancing the relationship of a merchant with its current or old customers and to encourage customer loyalty and repeat business.
• Sending emails with the purpose of acquiring new customers or convincing old customers to buy something immediately.
• Adding advertisements in emails sent by other companies to their customers.
• Emails that are being sent on the Internet (Email did and does exist outside the Internet, Network Email, FIDO etc.)

Source: Wikipedia
What is online media?
Advertising your banner or text ads on external websites is considered online media.
Example of the bigger publishers in SA are 24.com sites, MSN, iafrica.com however smaller sites may prove to be better placed for you brand such as wwww.fasa.co.za for anybody selling to franchises

What are CPM and CPC?
CPM: Cost per thousand impressions.

Each time your ad is shown to a potential audience that is counted as an impression. You are paying for the number of times the page your ad appears on is viewed. Most publishers charge from R180 – R350 cpm. Click throughs to your site are not guaranteed but this model is great for branding campaigns and allow creative exectuions
CPC: Cost per click.

Primarily used by Google CPC / PPC (pay per click) is a model where the advertiser pays the publisher only when someone clicks through their ad. Great for text ads aimed at people who know what they are looking for – best used when objective is targeted, high traffic flow.

What is Mobile Marketing?
Mobile Marketing can refer to one of two categories of marketing. First, and relatively new, is meant to describe marketing on or with a mobile device, such as a mobile phone. Second, and a more traditional definition, is meant to describe marketing in a moving fashion - for example - technology road shows or moving billboards.
Marketing on a mobile phone has become increasingly popular ever since the rise of SMS (Short Message Service) in the early 2000s in Europe and some parts of Asia when businesses started to collect mobile phone numbers and send off wanted (or unwanted) content.  Over the past few years SMS has become a legitimate advertising channel. Source:Wikipedia