Classified advertising (classifieds) is a form of advertising which is particularly common in newspapers, online and other periodicals, e.g. free ads papers or Pennysavers. Kamloops Daily News is the local daily newspaper. Kamloops.Kijiji.ca is the local classified site.

Classified advertising differs from standard advertising or business models in that it allows private individuals (not simply companies or corporate entities) to solicit sales for products and services.

Classified advertising is usually textually based and can consist of as little as the type of item being sold and a telephone number to call for more information. It can also have much more detail, such as name to contact, address to contact or visit, a detailed description of the product or products ("pants and sweaters, size 10" as opposed to "clothing", "red 1996 Pontiac Grand Prix" as opposed to "automobile"). There are generally no pictures or other graphics within the advertisement, although sometimes a logo may be used.

Classified advertising is called such because it is generally grouped within the publication under headings classifying the product or service being offered (headings such as Accounting, Automobiles, Clothing, Farm Produce, For Sale, For Rent, etc.) and is grouped entirely in a distinct section of the periodical, which makes it distinct from display advertising, which often contains graphics or other art work and which is more typically distributed throughout a publication adjacent to editorial content.

A hybrid of the two forms — classified display advertising — may often be found, in which categorized advertisements with larger amounts of graphical detail can be found among the text listings of a classified advertising section in a publication. Business opportunities often use classifieds to sell their services, usually employing 1-800 numbers. Classified ads are also among the tools used by many companies in recruitment for available job opportunities.

Printed classified ads are typically just a few column lines in length, and they often filled with abbreviations to save space and money.
 

As the online classified advertising sector develops, there is an increasing emphasis toward specialization. Vertical markets for classifieds are developing quickly along with the general marketplace for classifieds websites. Like search engines, classified websites are often vertical in nature with sites providing advertising platforms for niche markets of buyers of sellers.