Advertisement, Promotion and Marketing?

[Life]

I am writing an essay on e commerce and would like to have the following 3 topics:

Advertisement, Promotion, and Marketing

For me these are all so similar but maybe im wrong.
Which should go together and which should be taken as a topic all by itself?
So what if i put Advertisement & Promotion together.....and take Marketing as a topic by itself?
Does this make sense? Thanks

[Andy]

An advert is usually a paid subscription on TV, in magazines, in papers and on the side of a bus etc.

An advert can be called a promotion too, but a promotion could be when a company want to push something specific at a special price or discount, or a new service.

Marketing covers all aspects of these activities. Website marketing, social media marketing, tv marketing etc etc.

It's hard to differentiate between these three topics but not impossible.
Hope that helps.

[Alexis]

Marketing would can be taken as a topic, because advertisement, promotion is a strategy for marketing. But marketing is also different from market. Marketing is very important for commerce, especially in this internet era. So nowadays, e-marketing is a tendency.