The UV Index provides a daily and hourly forecast of the expected intensity of ultraviolet (UV) radiation from the sun. Some exposure to sunlight is enjoyable. However, too much sun can be dangerous. Overexposure to the sun's ultraviolet radiation can cause immediate damage, such as sunburn, and long-term problems, such as skin cancer and cataracts.
All polls are surveys based on samples drawn from parent populations. A poll's purpose is to make accurate inferences about that population from what is directly learned about the sample through questions the sampled persons answer. Knowledge of the sample is just a means to that end.
Push, or server push, describes a style of Internet-based communication where the request for a given transaction is initiated by the publisher or central server. It is contrasted with pull/get, where the request for the transmission of information is initiated by the receiver or client. Push services are often based on information preferences expressed in advance. This is called a publish/subscribe model. A client subscribes to various information channels provided by a server; whenever new content is available on one of those channels, the server pushes that information out to the client.