Advertising and promotion, both have taken birth from broader concept of Marketing. But their meanings and area of expertise is quite different.
Advertising mainly relates to messages which are sent directly sent to target through medium of newspapers, magazines, T.V, hoardings, radio etc. These advertisements act as a catalyst and serve as a medium to make your brand stand apart. Whereas promotion is method of announcing your brand, product or service which can be easily changed or modified instantly at the back-end. It mainly includes coupons, contests, event participation, rebates, discount offers, social media, free mailers and direct mailers to prospects.
In terms of targeting specific customers, visitor or viewer, advertising has a better chances than promotion. With promotions, you cant predict that who will see your messages as well as when can you get into advertising.
If we look into the root and basic concept behind both the activities, the core that comes out is pure business growth and sustainability in the longer run. Right mix of advertising and promotion helps the business in getting the right push and in right direction.