Terms of Service, also known as Terms of Use and Terms and Conditions, are the legal agreements between service providers and the service consumers. The person must agree to abide by the terms of service in order to use the offered service. Terms of service can also be merely a disclaimer, especially regarding the use of websites. Vague language and lengthy sentences used in these terms of service have caused concerns about customer privacy and raised public awareness in many ways.

A Terms of Service agreement is mainly used for legal purposes by companies which provide software or services, such as web browsers, e-commerce, web search engines, social media, and transport services.

A legitimate Terms of Service agreement is legally binding and may be subject to change. Companies can enforce the terms by refusing service. Customers can enforce by filing a lawsuit or arbitration case if they can show they were actually harmed by a breach of the terms. There is a heightened risk of data going astray during corporate changes, including mergers, divestitures, buyouts, downsizing, etc., when data can be transferred improperly.

A terms of service agreement typically contains sections pertaining to one or more of the following topics:

Among 102 companies marketing genetic testing to consumers in 2014 for health purposes, 71 had publicly available terms and conditions:

Among 260 mass market consumer software license agreements in 2010:

Among the terms and conditions of 31 cloud-computing services in January-July 2010, operating in England:

The researchers note that rules on location and time limits may be unenforceable for consumers in many jurisdictions with consumer protections, that acceptable use policies are rarely enforced, that quick deletion is dangerous if a court later rules the termination wrongful, that local laws often require warranties (and UK forced Apple to say so).