监视是指对行为、活动或其他变动中信息的一种持续性关注，通常是为了对人达成影响、管理、指导或保护的目的。.监视可能带来正面或负面的效果，并有时候是以秘密的方式进行。在大多数的情况下，是由政府机构对个人或群体的观察（但也有例外的情况，例如疾病监视是指对疾病在社区中的传染等状况进行监视，而非直接针对个人进行观察或监控）。

对于政府和执法单位来说，监视是一种能维持社会控制、察觉并关注各种威胁，以及避免或调查犯罪活动的一种有效工具。随着保括高速监视电脑和生物特征识别软件等的科技演进，以及如通信协助执法法等法律的创建，政府现在拥有前所未有的能力来监控各种对象的活动。

Surveillance (/sərˈveɪ.əns/ or /sərˈveɪləns/) is the monitoring of the behavior, activities, or other changing information, usually of people for the purpose of influencing, managing, directing, or protecting them. This can include observation from a distance by means of electronic equipment (such as CCTV cameras), or inte****tion of electronically transmitted information (such as Internet traffic or phone calls); and it can include simple, relatively no- or low-technology methods such as human intelligence agents and postal inte****tion. The word surveillance comes from a French phrase for "watching over" ("sur" means "from above" and "veiller" means "to watch"), and is in contrast to more recent developments such as sousveillance.