Classified advertisement is arranged according to specific categories or classifications. The text of the advertisements is set in the same size and style of type and the ads are usually without illustration. The three major headings are Employment, Real Estate, and Automotive, although there are many additional categories (e.g., Business Opportunities, Lost and Found, Pets, Personals, and Legal Notices). Classified advertising is usually located in its own separate section of the publication and has its own rate card.
It is just like what you see on the news papers.. its full advertisement.. selling or offering products and service.. it helps to increase sales, and site popularity..
Classifieds are local advertisement in various local websites/ directories like sulekha and others. By which You can put your like an advertisement. Classifieds are very popular in SEO which are used to promote a website in local areas or to get high traffic. Thanx