Definition: A view is a representation of a SQL statement that is stored in memory so that it can be re-used. A view is a logical entity or logical table that is essentially a SQL statement stored in the database in the system tablespace.
As it turns out, it's very likely that your Facebook and Twitter messages are better protected from government snoops than your phone texts, even when you send them from the same device.
A push notification is a way for an app to send you a message or to notify you without you actually opening the app. The notification is pushed to you without you needing to do anything. You can think of it like the app sending you a text message, although notifications can take on several different forms. One common push notification takes the form of a red circle with a number in it that appears on the corner of the app's icon.