An advertisement is a public announcement promoting a product, service or idea through popular media like newspapers, magazines, TV, radio or cinema. The purpose is to attract attention and influence people in a persuasive way. There are two main types - classified and commercial. Classified ads are short, concise and categorized, providing relevant contact details. Commercial ads are larger and more expensive, using visually attractive designs, slogans and images to promote companies, products or events in an eye-catching way. Color schemes and certain colors are used to elicit different emotional responses from viewers.